Editing Orders of magnitude (length)

{{Short description|Comparison of a wide range of lengths}}
{{More citations needed|date=January 2020}}
{{Use dmy dates|date=August 2023}}

[[File:Orders of magnitude (english annotations).png|thumb|300px|upright=2|Objects of sizes in different order of magnitude (at inconsistent intervals)]]
[[File:Scales of size.jpg|thumb|300px|Graphical overview of sizes]]

The following are examples of [[order of magnitude|orders of magnitude]] for different [[length]]s.

==Overview==
{| class="wikitable"px"
|-
! rowspan=2 | Scale !! colspan=2 | Range ([[metre|m]]) !! rowspan=2 | Unit !! rowspan=2 | Example items
|-
! ≥ !! <
|-
| rowspan="3" |[[#Subatomic scale|Subatomic]]
|–
| 0
|–
| [[Gravitational singularity]]
|-
| 10<sup>−36</sup> || 10<sup>−33</sup>||{{math|[[Planck length|<var>ℓ</var><sub>P</sub>]]}}|| Fixed value (not a range). [[Quantum foam]], [[string (physics)|string]]
|-
| 10<sup>−18</sup> || 10<sup>−15</sup> || [[attometre|am]] || [[Proton]], [[neutron]], [[pion]]
|-
| rowspan=3 | [[#Atomic to cellular scale|Atomic to cellular]] || [[#1E-15|10<sup>−15</sup>]] || 10<sup>−12</sup> || [[femtometre|fm]] || [[Atomic nucleus]]
|-
| [[#1E-12|10<sup>−12</sup>]] || 10<sup>−9</sup> || [[picometre|pm]] || [[Wavelength]] of [[gamma ray]]s and [[X-ray]]s, [[hydrogen atom]]
|-
| [[#1E-9|10<sup>−9</sup>]] || 10<sup>−6</sup> || [[nanometre|nm]] || [[DNA]] [[helix]], [[virus]], wavelength of [[optical spectrum]], transistors used in CPUs
|-
| rowspan=2 | [[#Cellular to human scale|Cellular to human]] || [[#1E-6|10<sup>−6</sup>]] || 10<sup>−3</sup> || [[micrometre|μm]] || [[Bacterium]], [[fog]] water droplet, human [[hair]]'s diametre<ref name="Note Physics Factbook" group=note>The [[diametre]] of human hair ranges from 17 to 181 μm {{cite web|url=https://hypertextbook.com/facts/1999/BrianLey.shtml|title=Diametre of a human hair|first=Brian|last=Ley|year=1999|website=The Physics Factbook|editor-last=Elert|editor-first=Glenn|access-date=8 December 2018}}</ref>
|-
| [[#1E-3|10<sup>−3</sup>]] || 1 || [[millimetre|mm]] || [[Mosquito]], [[golf ball]], [[domestic cat]], [[violin]], [[football (association football)|football]]
|-
| rowspan=2 | [[#Human to astronomical scale|Human to astronomical]] || 1 || 10<sup>3</sup> || [[metre|m]] || [[Piano]], [[human]], [[automobile]], [[sperm whale]], [[association football#Pitch|football field]], [[Eiffel Tower]]
|-
| [[#1E3|10<sup>3</sup>]] || 10<sup>6</sup> || [[kilometre|km]] || [[Mount Everest]], length of [[Panama Canal]] and [[Trans-Siberian Railway]], larger [[asteroid]]
|-
| rowspan=7 | [[#Astronomical scale|Astronomical]] || [[#1E6|10<sup>6</sup>]] || 10<sup>9</sup> || [[#1 megametre|Mm]] || The [[Moon]], Earth, one [[light-second]]
|-
| [[#1E9|10<sup>9</sup>]] || 10<sup>12</sup> || [[#1 gigametre|Gm]] || [[Sun]], one [[light-minute]], [[Earth's orbit]]
|-
| [[#1E12|10<sup>12</sup>]] || 10<sup>15</sup> || [[#1 terametre|Tm]] || Orbits of [[outer planets]], [[Solar System]]
|-
| [[#1E15|10<sup>15</sup>]] || 10<sup>18</sup> || [[#1 petametre|Pm]] || A [[light-year]], the distance to [[Proxima Centauri]]
|-
| [[#1E18|10<sup>18</sup>]] || 10<sup>21</sup> || [[#1 exametre|Em]] || [[Spiral arm|Galactic arm]]
|-
| [[#1E21|10<sup>21</sup>]] || 10<sup>24</sup> || [[#1 zettametre|Zm]] || [[Milky Way]], distance to [[Andromeda Galaxy]]
|-
| [[#1E24|10<sup>24</sup>]] || 10<sup>27</sup> || [[#1 yottametre|Ym]] || [[Huge-LQG]], [[Hercules–Corona Borealis Great Wall]], [[Observable universe]]
|}
{{Clear}}

==Detailed list==
To help compare different orders of magnitude, the following list describes various lengths between <math>1.6 \times 10^{-35}</math>&nbsp;metres and <math>10^{10^{10^{122}}}</math>metres.

===Subatomic scale===
{| class="wikitable"
! Factor ([[metre|m]])
! Multiple
! Value
! Item
|-
| 0
| 0
| 0
| [[Gravitational singularity|Singularity]]
|-
|10<sup>−35</sup>
| 1 [[Planck length]]
| 0.0000162&nbsp;qm&nbsp;
| [[Planck length]]; typical scale of hypothetical [[loop quantum gravity]] or size of a hypothetical [[string (physics)|string]] and of [[brane]]s; according to [[string theory]], lengths smaller than this do not make any [[physics|physical]] sense.<ref name="Burgess_and_Quevedo">{{cite journal|first1=Cliff|last1=Burgess|first2=Fernando|last2=Quevedo|author2-link=Fernando Quevedo|title=The Great Cosmic Roller-Coaster Ride|url=https://www.scientificamerican.com/article/the-great-cosmic-roller-coaster-ride/ |journal=[[Scientific American]] |page=55|date=November 2007|volume=297|issue=5|doi=10.1038/scientificamerican1107-52|doi-broken-date=2 November 2024 |pmid=17990824|bibcode=2007SciAm.297e..52B|access-date=1 May 2017|url-access=subscription}}</ref> [[Quantum foam]] is thought to exist at this scale.
|-
| 10<sup>−24</sup>
| [[#Less than 1 zeptometre|1 yoctometre]] ([[yoctometre|ym]])
| 142 ym
| Effective [[cross section (physics)|cross section]] radius of 1 [[MeV]] [[neutrino]]s<ref>{{cite web|first=Carl R.|last=Nave|url=http://hyperphysics.phy-astr.gsu.edu/hbase/particles/cowan.html#c1 |title=Cowan and Reines Neutrino Experiment |work=[[HyperPhysics]]|access-date=4 December 2008}} (6.3 × 10<sup>−44</sup> cm<sup>2</sup>, which gives an effective radius of about 1.42 × 10<sup>−22</sup> m)</ref>
|-
|rowspan=3 | 10<sup>−21</sup>
|rowspan=3 | [[#1 zeptometre|1 zeptometre]] ([[zeptometre|zm]])
|
| [[Preon]]s, hypothetical particles proposed as subcomponents of quarks and leptons; the upper bound for the width of a [[cosmic string]] in string theory
|-
| 7 zm
| Effective cross section radius of high-energy [[neutrino]]s<ref name="NaveN3">{{cite web|first=Carl R.|last=Nave|url=http://hyperphysics.phy-astr.gsu.edu/hbase/particles/neutrino3.html#c2|title=Neutron Absorption Cross-sections |work=[[HyperPhysics]]|access-date=4 December 2008}} (area for 20 GeV about 10 × 10<sup>−42</sup> m<sup>2</sup> gives effective radius of about 2 × 10<sup>−21</sup> m; for 250 GeV about 150 × 10<sup>−42</sup> m<sup>2</sup> gives effective radius of about 7 × 10<sup>−21</sup> m)</ref>
|-
| 310 zm
| [[De Broglie wavelength]] of [[protons]] at the [[Large Hadron Collider]] (4 TeV {{as of|2012|lc=y||df=}})
|-
|rowspan=3 | 10<sup>−18</sup>
|rowspan=3 | [[#1 attometre|1 attometre]] ([[attometre|am]])
|rowspan=3 |
| Upper limit for the size of [[quark]]s and [[electron]]s
|-
| Sensitivity of the [[LIGO]] detector for [[gravitational wave]]s<ref>{{cite journal |quote=On 14 September 2015 at 09:50:45 UTC the two detectors of the Laser Interferometre Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10<sup>−21</sup>.|doi = 10.1103/PhysRevLett.116.061102|pmid = 26918975|title = Observation of Gravitational Waves from a Binary Black Hole Merger|journal = Physical Review Letters|volume = 116|issue = 6|pages = 061102|year = 2016|last1 = Abbott|first1 = B. P. |display-authors =etal |bibcode = 2016PhRvL.116f1102A|arxiv = 1602.03837|s2cid = 124959784}}</ref>
|-
| Upper bound of the typical size range for "fundamental [[string (physics)|strings]]"<ref name="Burgess_and_Quevedo"/>
|-
|| 10<sup>−17</sup>
|| [[#10 attometres|10 am]]
||
| Range of the [[weak force]]
|-
|| 10<sup>−16</sup>
|| [[#100 attometres|100 am]]
|| 850 am
| Approximate proton radius<ref>{{cite journal |last=Pohl |first=R. |display-authors=etal |title=The size of the proton|journal=Nature|volume=466|issue=7303|pages=213–6|date=July 2010|pmid=20613837|doi=10.1038/nature09250|bibcode=2010Natur.466..213P|s2cid=4424731 |url=https://rdcu.be/bYa2m |url-access=subscription}}</ref>
|}

===Atomic to cellular scale===
<!-- No more than three examples per row: choose examples from a range of sizes, and add extra examples to the sub-SECTIONs instead. -->
{| class="wikitable"
!Factor ([[metre|m]])
!Multiple
!Value
!Item
|-
|rowspan=5 | 10<sup>−15</sup>{{Anchor|1E-15}}
|rowspan=5 | [[#1 femtometre|1 femtometre]] ([[femtometre|fm]], fermi)
|1 fm
|Approximate limit of the [[gluon]]-mediated [[strong interaction|color force]] between [[quark]]s<ref name=profmattstrassler/><ref name=Kolena_at_Duke/>
|-
|1.5 fm
|Effective cross section radius of an 11 MeV [[proton]]<ref name="Nav">{{cite web |author=Nave, Carl R. |url=http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/crosec.html |title=Scattering cross section |access-date=10 February 2009}}
(diametre of the [[cross section (physics)|scattering cross section]] of an 11 MeV [[proton]] with a target proton)<!-- To verify, use online form with these figures: Z=1 KE=11 A=1 and obtain cross section of 1.758 fm^2; use Area=Pi*R^2 to derive diametre (2R) --></ref>
|-
|2.81794 fm
|[[Classical electron radius]]<ref>{{cite web|publisher=[[National Institute of Standards and Technology|NIST]] |url=https://physics.nist.gov/cgi-bin/cuu/Value?re|title=CODATA Value: classical electron radius |website=The NIST Reference on Constants, Units, and Uncertainty}}</ref>
|-
|3 fm
|Approximate limit of the [[meson]]-mediated [[strong interaction|nuclear binding force]]<ref name=profmattstrassler>{{cite web |url=http://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-known-forces-of-nature/the-strength-of-the-known-forces/ |title=The strength of the known forces |first=Matt |last=Strassler |author-link=Matt Strassler|website=profmattstrassler.com|date=30 May 2013 }}</ref><ref name=Kolena_at_Duke>{{cite web |url=http://webhome.phy.duke.edu/~kolena/modern/forces.html#005 |title=The four forces: The strong interaction |author-last=Kolena |publisher=Duke University |department=Astrophysics Dept website}}</ref>
|-
|750 to 822.25 fm
|Longest [[wavelength]] of [[gamma ray]]s
|-
| rowspan="4" |10<sup>−12</sup>{{Anchor|1E-12}}
| rowspan="4" |[[#1 picometre|1 picometre]] ([[picometre|pm]])
|1.75 to 15 fm
|Diametre range of the [[atomic nucleus]]<ref name="Burgess_and_Quevedo" /><ref>{{cite web|title=The Scale of the Universe|url=https://cass.ucsd.edu/archive/public/tutorial/scale.html|author=H. E. Smith|publisher=[[University of California, San Diego|UCSD]]|quote=~10<sup>−13</sup>cm|access-date=10 February 2009}}</ref>
|-
|1 pm
|Distance between [[atomic nuclei]] in a [[white dwarf]]
|-
|2.4 pm
|[[Compton wavelength]] of [[electron]]
|-
|5 pm
|Wavelength of shortest [[X-ray]]s
|-
| rowspan="2" |10<sup>−11</sup>
| rowspan="2" |[[#10 picometres|10 pm]]
|28 pm
|Radius of [[helium]] atom
|-
|53 pm
|[[Bohr radius]] (radius of a [[hydrogen atom]])
|-
|rowspan=4 | 10<sup>−10</sup>
|rowspan=4 | [[#100 picometres|100 pm]]
|100 pm
|1 [[ångström]] (also [[covalent radius]] of [[sulfur]] atom<ref>{{cite web|first=Mark|last=Winter|title=WebElements Periodic Table of the Elements / Sulfur / Radii|url=https://www.webelements.com/sulfur/atom_sizes.html|date=2008|access-date=6 December 2008}}</ref>)
|-
|154 pm
|Length of a typical [[covalent bond]] ([[carbon|C]]–C)
|-
|280 pm
|Average size of the [[water]] molecule (actual lengths may vary)
|-
|500 pm
|Width of [[protein]] [[alpha helix|α helix]]
|-
|rowspan=5 | 10<sup>−9</sup>{{Anchor|1E-9}}
|rowspan=5 | [[#1 nanometre|1 nanometre]] ([[nanometre|nm]])
|1&nbsp;nm
|Diametre of a [[carbon nanotube]]<ref>{{cite journal|vauthors=Flahaut E, Bacsa R, Peigney A, Laurent C|title=Gram-scale CCVD synthesis of double-walled carbon nanotubes|journal=Chemical Communications|volume=12|issue=12|pages=1442–3|date=June 2003|pmid=12841282|doi=10.1039/b301514a|s2cid=30627446 |url=https://hal.archives-ouvertes.fr/hal-00926035/file/Flahaut_10551.pdf}}</ref> Diametre of smallest transistor gate (as of 2016)<ref>{{Cite web|url=https://www.theverge.com/circuitbreaker/2016/10/6/13187820/one-nanometre-transistor-berkeley-lab-moores-law|title = The world's smallest transistor is 1nm long, physics be damned|date = 6 October 2016}}</ref>
|-
|2&nbsp;nm
|Diametre of the [[DNA]] helix<ref>{{cite web|last=Stewart|first=Robert|title=Dr|url=http://rh.healthsciences.purdue.edu/vc/theory/dna/index.html|website=Radiobiology Software|archive-url=https://web.archive.org/web/20100630161605/http://rh.healthsciences.purdue.edu/vc/theory/dna/index.html|archive-date=30 June 2010|access-date=20 May 2015|url-status=dead}}</ref>
|-
|2.5&nbsp;nm
|Smallest [[microprocessor]] [[transistor]] [[Gate (transistor)|gate]] oxide thickness ({{as of|lc=y|2007|January}}){{Citation needed|date=April 2020}}
|-
|3.4&nbsp;nm
|Length of a [[DNA]] [[turn (biochemistry)|turn]] (10 [[Base pair|bp]])<ref>{{cite book|title=DNA Interactions with Polymers and Surfactants|publisher=John Wiley & Sons, Inc.|location=Hoboken, NJ|isbn=978-0-470-25818-7|page=265|first=Dominique|last=Langevin|editor-first1=Rita S|editor-last1=Dias|editor-first2=Bjorn|editor-last2=Lindman|doi=10.1002/9780470286364.ch10|chapter=Chapter 10: DNA-Surfactant/Lipid Complexes at Liquid Interfaces|quote=DNA has 20 elementary charges per helical turn over the corresponding length of 3.4nm|year=2008}}</ref>
|-
|6–10&nbsp;nm
|Thickness of [[cell membrane]]
|-
|rowspan=4 | 10<sup>−8</sup>
|rowspan=4 | [[#10 nanometres|10&nbsp;nm]]
|10&nbsp;nm
|Upper range of thickness of [[cell wall]] in [[Gram staining|Gram]]-negative [[bacteria]]<ref>{{cite journal|last=Mai-Prochnow|first=Anne|date=2016-12-09|title=Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma|journal=Scientific Reports|publisher=Nature|volume=6|page=38610 |doi=10.1038/srep38610 |pmid=27934958 |pmc=5146927 |bibcode=2016NatSR...638610M }}</ref>
|-
|10&nbsp;nm
|{{as of|2016}}, the [[10 nanometre|10 nanometre]] was the smallest [[semiconductor device fabrication]] [[semiconductor node|node]]<ref>{{cite web|url=https://www.sammobile.com/2016/10/17/samsung-announces-industry-first-mass-production-of-system-on-chip-with-10nm-finfet-technology/|title=Samsung announces industry-first mass production of System-on-Chip with 10nm FinFET technology|last=F.|first=Adnan|website=SamMobile|date=17 October 2016 }}</ref>
|-
|40&nbsp;nm
|Extreme [[ultraviolet]] wavelength
|-
|50&nbsp;nm
|[[Flying height]] of the [[disk read-and-write head|head]] of a [[hard disk]]<ref>{{cite web|title=Hard drive basics – Capacities, RPM speeds, interfaces, and mechanics|url=https://www.helpwithpcs.com/hardware/hard-drive-basics.php|website=helpwithpcs.com|access-date=13 July 2016}}</ref>
|-
|rowspan=3 | 10<sup>−7</sup>
|rowspan=3 | [[#100 nanometres|100&nbsp;nm]]
|121.6&nbsp;nm
|Wavelength of the [[Lyman-alpha line]]<ref name="ber">Cohn, J. [[University of California, Berkeley]] [http://astro.berkeley.edu/~jcohn/lya.html Lyman alpha systems and cosmology]. Retrieved 21 February 2009.</ref>
|-
|120&nbsp;nm
|Typical diametre of the [[human immunodeficiency virus]] (HIV)<ref>{{cite book|last1=Seth|first1=S.D.|last2=Seth|first2=Vimlesh|title=Textbook of Pharmacology|date=2009|publisher=Elsevier|isbn=978-81-312-1158-8|page=X111|edition=3rd|url=https://books.google.com/books?id=51ozlZRBvQwC&pg=SL24-PA111}}</ref>
|-
|400–700&nbsp;nm
|Approximate wavelength range of [[visible light]]<ref name="hyp">{{cite web|url=http://hyperphysics.phy-astr.gsu.edu/hbase/vision/specol.html#c1|title=Color|website=[[HyperPhysics]]|date=2016|last=Nave|first=Carl R|publisher=Georgia State University}}</ref>
|}


===Cellular to human scale===
<!--Grouping entities like red blood cells and Disneyland together doesn't feel appropriate. It should be subdivided, or at least merged into the smaller scale -->
{| class="wikitable"
!Factor ([[metre|m]])
!Multiple
!Value
!Item
|-
|rowspan=3 | 10<sup>−6</sup>{{Anchor|1E-6}}
|rowspan=3 | [[#1 micrometre|1 micrometre]] ([[micrometre|μm]])
(also called 1 micron)
|1–4&nbsp;μm
|Typical length of a bacterium<ref>{{cite web|title=Size of bacteria|url=http://www.whatarebacteria.com/size-of-bacteria/|website=What are bacteria?|access-date=19 July 2016}}</ref>
|-
|4&nbsp;μm
|Typical diametre of [[spider silk]]<ref>{{cite web|title=Engineering properties of spider silk|url=http://web.mit.edu/course/3/3.064/www/slides/Ko_spider_silk.pdf|website=web.mit.edu|last1=Ko|first1=Frank K.|last2=Kawabata|first2=Sueo|last3=Inoue|first3=Mari|last4=Niwa|first4=Masako|last5=Fossey|first5=Stephen|last6=Song|first6=John W.}}</ref>
|-
|7&nbsp;μm
|Typical size of a [[red blood cell]]<ref>{{cite web|last1=Doohan|first1=Jim|title=Blood cells|url=http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm|website=biosbcc.net|access-date=19 July 2016|url-status=dead|archive-url=https://web.archive.org/web/20160723113019/http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm|archive-date=23 July 2016}}</ref>
|-
|rowspan=4 | 10<sup>−5</sup>
|rowspan=4 | [[#10 micrometres|10&nbsp;μm]]
|10&nbsp;μm
|Typical size of a fog, mist, or cloud water droplet
|-
|10&nbsp;μm
|Width of [[transistor]]s in the [[Intel 4004]], the world's first commercial [[microprocessor]]
|-
|12&nbsp;μm
|Width of [[acrylic fiber]]
|-
|17–181&nbsp;μm
|Width range of human hair<ref name="Physics Factbook">According to ''The [[Physics]] Factbook'', the diametre of human hair ranges from 17 to 181&nbsp;μm{{cite web|url=https://hypertextbook.com/facts/1999/BrianLey.shtml|title=Width of a Human Hair|last=Ley|first=Brian|website=The Physics Factbook|year=1999}}</ref>
|-
|rowspan=3 | 10<sup>−4</sup>
|rowspan=3 | [[#100 micrometres|100&nbsp;μm]]
|340&nbsp;μm
|Size of a [[pixel]] on a 17-inch monitor with a resolution of 1024×768
|-
|560&nbsp;μm
|Thickness of the central area of a human [[cornea]]<ref name="ReferenceA">{{cite journal|vauthors=Liu Z, Huang AJ, Pflugfelder SC|title=Evaluation of corneal thickness and topography in normal eyes using the Orbscan corneal topography system|journal=The British Journal of Ophthalmology|volume=83|issue=7|pages=774–8|date=July 1999|pmid=10381661|pmc=1723104|doi=10.1136/bjo.83.7.774}}</ref>
|-
|750&nbsp;μm
|Maximum diametre of ''[[Thiomargarita namibiensis]]'', the second largest bacterium ever discovered
|-
|rowspan=3 | 10<sup>−3</sup>{{Anchor|1E-3}}
|rowspan=3 | [[#1 millimetre|1 millimetre]] ([[millimetre|mm]])
|~5&nbsp;mm
|Length of an average [[flea]] is 1–10&nbsp;mm (usually <5&nbsp;mm)<ref name=BugGuide>[https://bugguide.net/node/view/7040 Order Siphonaptera – Fleas – BugGuide.Net] Accessed 29 April 2014</ref>
|-
|2.54&nbsp;mm
|One-tenth inch; distance between pins in [[dual in-line package|DIP]] (dual-inline-package) electronic components
|-
|5.70&nbsp;mm
|Diametre of the projectile in [[5.56×45mm NATO]] ammunition
|-
|rowspan=3 | 10<sup>−2</sup>
|rowspan=3 | [[#1 centimetre|1 centimetre]] ([[centimetre|cm]])
|20&nbsp;mm
|Approximate width of an adult human [[finger]]
|-
|54&nbsp;mm × 86&nbsp;mm
|Dimensions of a [[credit card]], according to the [[ISO/IEC 7810 ID-1]] standard
|-
|73–75&nbsp;mm
|Diametre of a [[Baseball (ball)|baseball]], according to [[Major League Baseball]] guidelines<!-- Calculated from requirement that the circumference be 9 to 9.25 inches: 9*2.54/pi=73 mm. 9.25*2.54/pi=75 mm --><ref name="Official Rules">{{cite web|title=Official Rules|url=http://mlb.mlb.com/mlb/official_info/official_rules/official_rules.jsp|publisher=MLB|access-date=30 September 2011}}</ref>
|-
|rowspan=3 | 10<sup>−1</sup>
|rowspan=3 | [[#1 decimetre|1 decimetre]] ([[decimetre|dm]])
|120&nbsp;mm
|Diametre of a [[compact disc]]
|-
|660&nbsp;mm
|Length of the longest [[pine]] cones, produced by the [[sugar pine]]<ref>{{cite web|url=http://www.na.fs.fed.us/Spfo/pubs/silvics_manual/Volume_1/pinus/lambertiana.htm|title=Pinus lambertiana|author1=Bohun B. Kinloch Jr|author2=William H. Scheuner|access-date=19 January 2017|archive-date=8 June 2011|archive-url=https://web.archive.org/web/20110608015717/http://www.na.fs.fed.us/Spfo/pubs/silvics_manual/Volume_1/pinus/lambertiana.htm|url-status=dead}}</ref>

|-
|900&nbsp;mm
|Average length of a [[rapier]], a [[fencing]] sword<ref name="2-Clicks Swords">{{cite web|url=https://www.2-clicks-swords.com/article/what-is-a-rapier.html|title=What is a rapier – Renaissance swords Rapiers|publisher=2-Clicks Swords}}</ref>
|}

===Human to astronomical scale===
[[File:Size planets comparison.jpg|thumb|right|Planets of the Solar System to scale]]
{| class="wikitable"
!Factor ([[metre|m]])
!Multiple
!Value
!Item
|-
|rowspan=3 | 1 (10<sup>0</sup>){{Anchor|1E0}}
|rowspan=3 | [[#1 metre|1 metre]] ([[metre|m]])
|1&nbsp;m (exactly)
|Since 2019, defined as the length of the path travelled by [[Light#Speed of light|light in a vacuum]] during a time interval of 1/299,792,458 of a [[second]], where the second is defined by a hyperfine transition frequency of [[caesium]].
|-
|2.72&nbsp;m
|Height of [[Robert Wadlow]], tallest-known human.<ref name="Guinness">{{cite web|url=http://www.guinnessworldrecords.com/records/hall-of-fame/robert-wadlow-tallest-man-ever|title=Robert Wadlow: Tallest man ever|publisher=[[Guinness World Records]]}}</ref>
|-
|8.38 m
|Length of a London bus ([[AEC Routemaster]])
|-
|rowspan=3 | 10<sup>1</sup>
|rowspan=3 | [[#1 decametre|1 decametre]] ([[decametre|dam]])
|33 m
|Length of the longest-known [[blue whale]]<ref>{{cite web|url=http://nationalzoo.si.edu/Animals/AnimalRecords/|title=Animal Records|publisher=Smithsonian National Zoological Park|url-status=dead|archive-url=https://web.archive.org/web/20040823234342/http://nationalzoo.si.edu/Animals/AnimalRecords/|archive-date=23 August 2004}}</ref>
|-
|52 m
|Height of the [[Niagara Falls]]<ref name="Niagara Parks Commission">{{cite web|title=Niagara Falls Geology Facts & Figures|url=http://www.niagaraparks.com/media/geology-facts-figures.html|publisher=Niagara Parks Commission|access-date=29 June 2011|url-status=dead|archive-url=https://web.archive.org/web/20110719093559/http://www.niagaraparks.com/media/geology-facts-figures.html|archive-date=19 July 2011}}</ref>
|-
|93.47 m
|Height of the [[Statue of Liberty]]
|-
|rowspan=4 | 10<sup>2</sup>
|rowspan=4 | [[#1 hectometre|1 hectometre]] ([[hectometre|hm]])
|105 m
|Length of a typical [[association football|football]] field
|-
|137 m (147 m)
|Height (present and original) of the [[Great Pyramid of Giza]]
|-
|300 m
|Height of the [[Eiffel Tower]], one of the famous monuments of Paris
|-
|979 m
|Height of the [[Salto Angel]], the world's highest free-falling waterfall ([[Venezuela]])
|-
|rowspan=3 | 10<sup>3</sup>
|rowspan=3 | [[#1 kilometre|1 kilometre]] ([[kilometre|km]])
|2.3&nbsp;km
|Length of the [[Three Gorges Dam]], the largest [[dam]] in the world<ref name="Three Gorges Dam">{{cite web|url=https://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/three-gorges-dam|title=Three Gorges Dam|publisher=Cengage Learning|website=encyclopedia.com}}</ref><ref>{{Cite web|url=http://www.ibiblio.org/chinesehistory/contents/07spe/specrep01.html#Quick+Facts|title=Exploring Chinese History :: Special Reports :: The Three Gorges Dam Project|website=www.ibiblio.org}}</ref>
|-
|3.1&nbsp;km
|Narrowest width of the [[Strait of Messina]], separating [[Italy]] and [[Sicily]]
|-
|8.848&nbsp;km
|Height of [[Mount Everest]], the highest mountain on Earth
|-
|rowspan=3 | 10<sup>4</sup>
|rowspan=3 | [[#10 kilometres|10&nbsp;km]]<!-- a.k.a. the obsolete term myriametre -->
|10.9&nbsp;km
|Depth of the [[Challenger Deep]] in the [[Mariana Trench]], the deepest-known point on Earth's surface
|-
|27&nbsp;km
|Circumference of the [[Large Hadron Collider]], {{as of|May 2010|lc=on}} the largest and highest energy [[particle accelerator]]
|-
|42.195&nbsp;km
|Length of a [[marathon]]
|-
| rowspan="5" |10<sup>5</sup>
| rowspan="5" |[[#100 kilometres|100&nbsp;km]]
|100&nbsp;km
|The distance the [[IAU]] considers to be the limit to [[space]], called the [[Karman line]]
|-
|163&nbsp;km
|Length of the [[Suez Canal]], connecting the [[Mediterranean Sea]] to the [[Red Sea]]
|-
|491&nbsp;km
|Length of the [[Pyrenees]], the [[mountain range]] separating [[Spain]] and [[France]]
|-
|600&nbsp;km
|[[Thermosphere]] height 
|-
|974.6 km
|Greatest diametre of the dwarf planet [[Ceres (dwarf planet)|Ceres]].<ref name="ReferenceB">{{cite journal |vauthors=Thomas PC, Parker JW, McFadden LA, Russell CT, Stern SA, Sykes MV, Young EF |date=September 2005 |title=Differentiation of the asteroid Ceres as revealed by its shape |journal=Nature |volume=437 |issue=7056 |pages=224–6 |bibcode=2005Natur.437..224T |doi=10.1038/nature03938 |pmid=16148926 |s2cid=17758979}}</ref>
|-
| rowspan="9" | 10<sup>6</sup>{{Anchor|1E6}}
| rowspan="9" | [[#1 megametre|1 megametre]] ([[megametre|Mm]])
|2.38 Mm
|Diametre of dwarf planet [[Pluto]], formerly the smallest [[planet]] category<ref name="Asteroid-planet?" group=note>The exact [[Solar System#Terminology|category]] (asteroid, dwarf planet, or planet) to which particular Solar System objects belong, has been subject to some revision since the discovery of [[extrasolar planet]]s and [[trans-Neptunian object]]s</ref> in the Solar System
|-
|3.48 Mm
|Diametre of the [[Moon]]
|-
|5.2 Mm
|Typical distance covered by the winner of the [[24 Hours of Le Mans]] automobile endurance race
|-
|6.259 Mm
|Length of the [[Great Wall of China]]
|-
|6.371 Mm
|Average [[Earth radius|radius of Earth]]
|-
|6.378 Mm
|Equatorial radius of Earth
|-
|6.6 Mm
|Approximate length of the two longest rivers, the [[Nile]] and the [[Amazon River|Amazon]]
|-
|7.821 Mm
|Length of the [[Trans-Canada Highway]]
|-
|9.288 Mm
|Length of the [[Trans-Siberian Railway]], longest in the world
|}

===Astronomical scale===
{| class="wikitable"
!Factor ([[metre|m]])
!Multiple
!Value
!Item
|-
| rowspan="3" | 10<sup>7</sup>{{Anchor|1E7}}
| rowspan="3" | [[#10 megametres|10&nbsp;Mm]]
|12.756 Mm
|Equatorial diametre of Earth
|-
|20.004 Mm
|Length of a [[Meridian (geography)|meridian]] on Earth (distance between Earth's poles along the surface)<ref>{{Cite journal |last=Weintrit |first=Adam |date=2013 |title=So, What is Actually the Distance from the Equator to the Pole? – Overview of the Meridian Distance Approximations |url=http://www.transnav.eu/Article_So,_What_is_Actually_the_Distance_Weintrit,26,435.html |journal=TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation |language=en |volume=7 |issue=2 |pages=259–272 |doi=10.12716/1001.07.02.14 |issn=2083-6473|doi-access=free }}</ref>
|-
|40.075 Mm
|Length of Earth's [[equator]]
|-
|rowspan=3 | 10<sup>8</sup>{{Anchor|1E8}}
|rowspan=3 | [[#100 megametres|100&nbsp;Mm]]
|142.984 Mm
|Diametre of [[Jupiter]]
|-
|299.792 Mm
|Distance traveled by light in vacuum in one second (a [[light-second]], exactly 299,792,458 m by definition of the [[speed of light]])
|-
|384.4 Mm
|[[Moon]]'s orbital distance from Earth
|-
|rowspan=2 | 10<sup>9</sup>{{Anchor|1E9}}
|rowspan=2 | [[#1 gigametre|1 gigametre]] ([[gigametre|Gm]])
|1.39&nbsp;Gm
|Diametre of the [[Sun]]
|-
|5.15&nbsp;Gm
|Greatest mileage ever recorded by a car (3.2 million miles by a 1966 [[Volvo P1800|Volvo P-1800S]])<ref>{{cite web |title=Volvo owner Irv Gordon, who drove 3.2M miles in his P1800, has died |url=https://www.autoblog.com/2018/11/16/irv-gordon-dies-volvo-p1800-mileage-record/ |website=autoblog.com |access-date=23 January 2021 |date=16 November 2018}}</ref>
|-
| 10<sup>10</sup>{{Anchor|1E10}}
| [[#10 gigametres|10 Gm]]
|18 Gm
|Approximately one [[light-minute]]
|-
| rowspan=1 | 10<sup>11</sup>{{Anchor|1E11}}
| rowspan=1 | [[#100 gigametres|100 Gm]]
|150&nbsp;Gm
|1 [[astronomical unit]] (au); mean distance between Earth and Sun
|-
|rowspan=5 | 10<sup>12</sup>{{Anchor|1E12}}
|rowspan=5 | [[#1 terametre|1 terametre]] (Tm)
|1.3&nbsp;Tm
|Optical diametre of [[Betelgeuse]]
|-
|1.4&nbsp;Tm
|Orbital distance of [[Saturn]] from Sun
|-
|2&nbsp;Tm
|Estimated optical diametre of [[VY Canis Majoris]], one of the [[list of largest stars|largest-known stars]]
|-
|5.9&nbsp;Tm
|Orbital distance of Pluto from the Sun
|-
|~ 7.5&nbsp;Tm
|Outer boundary of the [[Kuiper belt]]
|-
|rowspan=4 | 10<sup>13</sup>{{Anchor|1E13}}
|rowspan=4 | [[#10 terametres|10 Tm]]
|
|Diametre of the [[Solar System]] as a whole<ref name="Burgess_and_Quevedo"/>
|-
|16.09&nbsp;Tm
|Total length of DNA molecules in all cells of an adult human body<ref>{{cite web|url=https://kqed.org/quest/1219/a-long-and-winding-dna|title=A Long and Winding DNA|last=Starr|first=Barry|date=2009-02-02|publisher=KQED|access-date=3 July 2024}}</ref>
|-
|21.49&nbsp;Tm
|Distance of the ''[[Voyager 1]]'' spacecraft from Sun ({{As of|2018|alt=as of Oct 2018}}), the farthest man-made object so far<ref>{{cite web|url=http://heavens-above.com/solar-escape.aspx|title=Spacecraft escaping the Solar System|access-date=19 October 2018|url-status=dead|archive-url=https://web.archive.org/web/20181007015036/https://www.heavens-above.com/SolarEscape.aspx|archive-date=7 October 2018|website=Heavens Above}}</ref>
|-
|62.03&nbsp;Tm
|Estimated radius of the [[event horizon]] of the [[supermassive black hole]] in [[NGC 4889]], the largest-known [[black hole]] to date
|-
|10<sup>14</sup>{{Anchor|1E14}}
|[[#100 terametres|100 Tm]]
|180&nbsp;Tm
|Size of the [[debris disk]] around the star [[51 Pegasi]]<ref>{{cite web|url=http://esciencenews.com/articles/2009/09/24/twin.keck.telescopes.probe.dual.dust.disks|title=Twin Keck telescopes probe dual dust disks|website=(e) Science News|date=24 September 2009}}</ref>
|-
|rowspan=2 | 10<sup>15</sup>{{Anchor|1E15}}
|rowspan=2 | [[#1 petametre|1 petametre]] (Pm)
|~7.5&nbsp;Pm
|Supposed outer boundary of the [[Oort cloud]] (~ 50,000 au)
|-
|9.461&nbsp;Pm
|Distance traveled by light in vacuum in one year; at its current speed, ''Voyager 1'' would need 17,500 years to travel this distance
|-
|rowspan=3 | 10<sup>16</sup>{{Anchor|1E16}}
|rowspan=3 | [[#10 petametres|10 Pm]]
|30.857&nbsp;Pm
|1 [[parsec]]
|-
|39.9&nbsp;Pm
|Distance to nearest star ([[Proxima Centauri]])
|-
|41.3&nbsp;Pm
|As of March 2013, distance to nearest discovered [[extrasolar planet]] ([[Alpha Centauri Bc]])
|-
|rowspan=2 | 10<sup>17</sup>{{Anchor|1E17}}
|rowspan=2 | [[#100 petametres|100 Pm]]
|193&nbsp;Pm
|As of October 2010, distance to nearest discovered extrasolar planet with potential to support life as presently defined by science ([[Gliese 581 d]])
|-
|615&nbsp;Pm
|Approximate radius of humanity's radio bubble, caused by high-power TV broadcasts leaking through the atmosphere into outer space
|-
||10<sup>18</sup>{{Anchor|1E18}}
||[[#1 exametre|1 exametre]] (Em)
|1.9&nbsp;Em
|Distance to nearby [[solar twin]] ([[HIP 56948]]), a star with properties virtually identical to the Sun<ref>{{cite magazine|last=Shiga|first=David|url=https://www.newscientist.com/article/dn12725-suns-twin-an-ideal-hunting-ground-for-alien-life.html|title=Sun's 'twin' an ideal hunting ground for alien life|magazine=New Scientist|access-date=3 October 2007}}</ref>
|-
|10<sup>19</sup>{{Anchor|1E19}}
|[[#10 exametres|10 Em]]
|9.46 Em
|Average thickness of [[Milky Way Galaxy]]<ref>{{cite web|last1=Christian|first1=Eric|last2=Samar|first2=Safi-Harb | authorlink2 = Samar Safi-Harb|title=How large is the Milky Way?|url=http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980317b.html|archive-url=https://web.archive.org/web/19990202064645/http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980317b.html|url-status=dead|archive-date=2 February 1999|access-date=14 November 2008}}</ref> (1,000 to 3,000 ly by [[Hydrogen line|21&nbsp;cm observations]]<ref>{{cite book|last=Duncan|first=Martin|title=Physics 216 – Introduction to Astrophysics|chapter=16|chapter-url=http://www.physics.queensu.ca/~phys216/ch16B.pdf|date=2008|access-date=14 November 2008|url-status=dead|archive-url=https://web.archive.org/web/20081217023721/http://www.physics.queensu.ca/~phys216/ch16B.pdf|archive-date=17 December 2008}}</ref>)
|-
|rowspan=1 | 10<sup>20</sup>{{Anchor|1E20}}
|[[#100 exametres|100 Em]]
|113.5 Em
|Thickness of [[Milky Way Galaxy]]'s gaseous disk<ref>{{cite web|url=http://news.smh.com.au/milky-way-fatter-than-first-thought/20080220-1tbv.html|title=Milky Way fatter than first thought|access-date=14 November 2008|date=20 February 2008|website=[[The Sydney Morning Herald]]|publisher=[[Australian Associated Press]]|url-status=dead|archive-url=https://web.archive.org/web/20080428132510/http://news.smh.com.au/milky-way-fatter-than-first-thought/20080220-1tbv.html|archive-date=28 April 2008}}</ref>
|-
|rowspan=6 | 10<sup>21</sup>{{Anchor|1E21}}
|rowspan=6 | [[#1 zettametre|1 zettametre]] (Zm)
|-
|1.54&nbsp;Zm
|Distance to [[Supernova 1987a|SN 1987A]], the most recent naked eye supernova
|-
|1.62&nbsp;Zm
|Distance to the [[Large Magellanic Cloud]] (a [[dwarf galaxy]] [[orbit]]ing the [[Milky Way]])
|-
|1.66&nbsp;Zm
|Distance to the [[Small Magellanic Cloud]] (another dwarf galaxy orbiting the Milky Way)
|-
|1.9&nbsp;Zm
|Diametre of galactic disk of [[Milky Way Galaxy]]<ref>{{cite journal|author=M. López-Corredoira |author2=C. Allende Prieto |author3=F. Garzón |author4=H. Wang |author5=C. Liu |author6=L. Deng |url=https://www.aanda.org/articles/aa/full_html/2018/04/aa32880-18/aa32880-18.html |title=Disk stars in the Milky Way detected beyond 25 kpc from its center|journal=[[Astronomy & Astrophysics]]|volume=612|pages=L8|doi=10.1051/0004-6361/201832880|year=2018|bibcode=2018A&A...612L...8L|arxiv=1804.03064|s2cid=59933365 }}</ref><ref>{{cite press release|first=David|last=Freeman|title=The Milky Way galaxy may be much bigger than we thought|url=https://www.nbcnews.com/mach/science/milky-way-galaxy-may-be-much-bigger-we-thought-ncna876966|date=25 May 2018|publisher=[[CNBC]]}}</ref><ref name="rpi2015">{{cite press release|first=Mary L.|last=Martialay|title=The Corrugated Galaxy—Milky Way May Be Much Larger Than Previously Estimated|url=http://news.rpi.edu/content/2015/03/09/rippling-milky-way-may-be-much-larger-previously-estimated|date=11 March 2015|publisher=[[Rensselaer Polytechnic Institute]]|archive-url=https://web.archive.org/web/20150313123405/http://news.rpi.edu/content/2015/03/09/rippling-milky-way-may-be-much-larger-previously-estimated|archive-date=13 March 2015}}</ref><ref>{{cite news|url=http://www.space.com/29270-milky-way-size-larger-than-thought.html|title=Size of the Milky Way Upgraded, Solving Galaxy Puzzle|work=Space.com|last=Hall|first=Shannon|date=4 May 2015|access-date=9 June 2015|url-status=live|archive-url=https://web.archive.org/web/20150607104254/http://www.space.com/29270-milky-way-size-larger-than-thought.html|archive-date=7 June 2015}}</ref>
|-
|6.15&nbsp;Zm
|Diametre of the low surface brightness disc halo of the giant spiral galaxy [[Malin 1]]
|-
|rowspan=4 | 10<sup>22</sup>{{Anchor|1E22}}
|rowspan=4 | [[#10 zettametres|10 Zm]]
|13.25&nbsp;Zm
| Radius of the diffuse stellar halo of [[IC 1101]], one of the largest-known galaxies
|-
|24&nbsp;Zm
|Distance to [[Andromeda Galaxy]]
|-
|30.857&nbsp;Zm
|1 [[megaparsec]]
|-
|50&nbsp;Zm
|Diametre of [[Local Group]] of [[galaxy|galaxies]]
|-
|10<sup>23</sup>{{Anchor|1E23"}}
|[[#100 zettametres|100 Zm]]
|300–600&nbsp;Zm
|Distance to [[Virgo cluster]] of [[galaxy|galaxies]]
|-
|rowspan=4 | 10<sup>24</sup>{{Anchor|1E24}}
|rowspan=4 | [[#1 yottametre|1 yottametre]] (Ym)
|2.19&nbsp;Ym
|Diametre of the [[Local Supercluster]] and the largest voids and filaments
|-
|2.8&nbsp;Ym
|[[End of Greatness]]
|-
|~5&nbsp;Ym
|Diametre of the [[Horologium Supercluster]]<ref>{{cite web|url=http://www.atlasoftheuniverse.com/superc/hor.html|title=The Horologium Supercluster|website=Atlas of the Universe}}</ref>
|-
|9.461&nbsp;Ym{{Anchor|1E25}}
|Diametre of the [[Pisces–Cetus Supercluster Complex]], the supercluster complex which includes Earth
|-
|rowspan=3 | 10<sup>25</sup>
|rowspan=3 | [[#10 yottametres|10 Ym]]
|13&nbsp;Ym
|Length of the [[Sloan Great Wall]], a giant wall of galaxies ([[galactic filament]])<ref>{{Cite journal |arxiv = astro-ph/0310571|bibcode = 2005ApJ...624..463G|title = A Map of the Universe|journal = The Astrophysical Journal|volume = 624|issue = 2|pages = 463|last1 = Gott|first1 = J. Richard|last2 = Jurić|first2 = Mario|last3 = Schlegel|first3 = David|last4 = Hoyle|first4 = Fiona|last5 = Vogeley|first5 = Michael|last6 = Tegmark|first6 = Max|last7 = Bahcall|first7 = Neta|last8 = Brinkmann|first8 = Jon|year = 2005|doi = 10.1086/428890|s2cid = 9654355}}</ref>
|-
|30.857&nbsp;Ym
|1 [[gigaparsec]]
|-
|37.84&nbsp;Ym
|Length of the [[Huge-LQG]], a group of 73 [[quasar]]s
|-
|rowspan=3 | 10<sup>26</sup>{{Anchor|1E26}}
|rowspan=3 | [[#100 yottametres|100 Ym]]
|95&nbsp;Ym
|Estimated [[distance measures (cosmology)|light travel distance]] to certain [[quasars]]. Length of the [[Hercules–Corona Borealis Great Wall]], a colossal wall of galaxies, the largest and the most massive structure in the observable universe as of 2014
|-
|127&nbsp;Ym
|Estimated light travel distance to [[GN-z11]], the [[list of the most distant astronomical objects|most distant object]] ever observed
|-
|870&nbsp;Ym
|Approximate diametre ([[comoving distance]]) of the [[visible universe]]<ref name="Burgess_and_Quevedo"/>
|-
|10<sup>27</sup>{{Anchor|1E27}}
|[[#1 ronnametre|1 Rm]]
<!-- previous version of this entry reported diametre as radius -->
|1.2&nbsp;Rm
|Lower bound of the (possibly infinite) radius of the universe, if it is a [[3-sphere]], according to one estimate using the [[Wilkinson Microwave Anisotropy Probe|WMAP]] data at 95% confidence<ref>{{cite journal|arxiv=astro-ph/0605709|title=How Many Universes Do There Need To Be?|last1=Scott|first1=Douglas|last2=Zibin|first2=J.P.|journal=International Journal of Modern Physics D|volume=15|number=12|pages=2229–2233|date=2006|doi=10.1142/S0218271806009662|bibcode=2006IJMPD..15.2229S|s2cid=119437678}}</ref> It equivalently implies that there are at minimum 21 [[particle horizon]]-sized volumes in the universe.
<!-- The article this entry is based on has been withdrawn by the author, specifically due to an error in the lower-bound estimate itself
|-
|3.8 Rm
|Lower bound of the homogeneous universe derived from the [[Planck spacecraft]]<ref>{{cite arxiv|arxiv=1304.1181|title=Inflationary Super-Hubble Waves and the Size of the Universe|first1=Thiago S.|last1=Pereira|first2=Luis Gustavo T.|last2=Silva|date=3 April 2013}}</ref>
-->
|-
|<math>10^{10^{115}}</math><ref name="exponents" group=note>10<sup>115</sup> is 1 followed by 115 zeroes, or a [[googol]] multiplied by a quadrillion. 10<sup>10<sup>115</sup></sup> is 1 followed by a quadrillion googol zeroes. 10<sup>10<sup>10<sup>122</sup></sup></sup> is 1 followed by 10<sup>10<sup>122</sup></sup> (a [[googolplex]]<sup>10 sextillion</SUP>) zeroes.</ref>
|<math>10^{10^{115}}</math> m
|<math>10^{10^{115}}</math> m
|According to the laws of probability, the distance one must travel until one encounters a volume of space identical to our [[observable universe]] with conditions identical to our own.<ref name="TegmarkPUstaple">{{Cite journal |pmid = 12701329|year = 2003|last1 = Tegmark|first1 = M.|title = Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations|journal = Scientific American|volume = 288|issue = 5|pages = 40–51|doi = 10.1038/scientificamerican0503-40|arxiv = astro-ph/0302131|bibcode = 2003SciAm.288e..40T}}</ref>
|-
|<math>10^{10^{10^{122}}}</math>
|<math>10^{10^{10^{122}}}</math> m
|<math>10^{10^{10^{122}}}</math> m
|Maximum size of universe after [[Inflation (cosmology)|cosmological inflation]], implied by one resolution of the [[Hartle–Hawking state|No-Boundary Proposal]]<ref>{{Cite journal|arxiv=hep-th/0610199|bibcode = 2007JCAP...01..004P|title=Susskind's challenge to the Hartle Hawking no-boundary proposal and possible resolutions|journal = Journal of Cosmology and Astro-Particle Physics|volume = 2007|issue = 1|pages = 004|last1 = Page|first1 = Don N.|last2 = Allende Prieto|first2 = C.|last3 = Garzon|first3 = F.|last4 = Wang|first4 = H.|last5 = Liu|first5 = C.|last6 = Deng|first6 = L.|date=18 October 2006|doi = 10.1088/1475-7516/2007/01/004|s2cid = 17403084}}</ref>
|}
<!-- Note: non-breaking space &nbsp; is not needed near the start of a line -->

== 1 quectometre and less ==

The ''{{vanchor|quectometre}}'' ([[SI]] symbol: ''{{vanchor|qm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;30</sup>&nbsp;[[metre]]s}}. 
To help compare different [[orders of magnitude]], this section lists [[length]]s shorter than 10<sup>−30</sup> [[metre|m]] (1 qm).
*1.6 × 10<sup>−5</sup> quectometres (1.6 × 10<sup>−35</sup> metres) – the [[Planck length]] (Measures of distance shorter than this do not make physical sense, according to current theories of [[physics]].)
*1 qm – 1 quectometre, the smallest named subdivision of the metre in the [[SI base unit]] of length, one nonillionth of a metre.<ref name="bipm.org"/>

== 1 rontometre ==
The ''{{vanchor|rontometre}}'' ([[SI]] symbol: ''{{vanchor|rm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;27</sup>&nbsp;[[metre]]s}}. 
*1 rm – 1 rontometre, a subdivision of the metre in the [[SI base unit]] of length, one octillionth of a metre.<ref name="bipm.org"/>

== 10 rontometres ==

*10 rm – the length of one side of a square whose area is one [[List of humorous units of measurement#Barn, outhouse, shed|shed]], a unit of [[Cross section (physics)|target cross section]] used in [[nuclear physics]]

==1 yoctometre ==
{{Anchor|Yoctometre}}
The ''{{vanchor|yoctometre}}'' ([[SI]] symbol: ''{{vanchor|ym}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;24</sup>&nbsp;[[metre]]s}}. 
*2 ym – the effective cross-section radius of 1&nbsp;[[MeV]] [[neutrino]]s as measured by [[Clyde Cowan]] and [[Frederick Reines]].<ref>{{cite web |first=Carl R. |last=Nave |url=http://hyperphysics.phy-astr.gsu.edu/hbase/particles/cowan.html#c1 |title=Cowan and Reines Neutrino Experiment |accessdate=2008-12-04}} ({{val|6.3|e=-44|u=cm2}}, which gives an effective radius of about {{val|2|e=-23|u=m}})</ref>

==1 zeptometre==

The ''{{vanchor|zeptometre}}'' ([[SI]] symbol: ''{{vanchor|zm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;21</sup>&nbsp;[[metre]]s}}. 
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−21</sup> [[metre|m]] and 10<sup>−20</sup> m (1 zm and 10 zm).

*2 zm – the upper bound for the width of a [[cosmic string]] in string theory.{{Citation needed|date=March 2018}}
*2 zm – radius of effective [[Cross section (physics)|cross section]] for a [[orders of magnitude (energy)#1E-9|20]] [[GeV]] [[neutrino]] scattering off a [[nucleon]]<ref name="NaveN3"/>
*7 zm – radius of effective cross section for a [[orders of magnitude (energy)#1E-9|250]]{{Broken anchor|date=2024-05-26|bot=User:Cewbot/log/20201008/configuration|target_link=orders of magnitude (energy)#1E-9|reason= The anchor (1E-9) [[Special:Diff/383862119|has been deleted]].}} GeV neutrino scattering off a nucleon<ref name="NaveN3"/>

==10 zeptometres==
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−20</sup> [[metre|m]] and 10<sup>−19</sup> m (10 [[Zeptometre|zm]] and 100 zm).

==100 zeptometres==
To help compare different [[orders of magnitude]], this section lists lengths between 10<sup>−19</sup> [[metre|m]] and 10<sup>−18</sup> m (100 [[zeptometre|zm]] and 1 [[Attometre|am]]).

*177 zm – [[de Broglie wavelength]] of [[protons]] at the [[Large Hadron Collider]] (7 TeV as of 2010){{Citation needed|date=March 2018}}

==1 attometre==

The ''{{vanchor|attometre}}'' ([[SI]] symbol: ''{{vanchor|am}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;18</sup>&nbsp;[[metre]]s}}. 
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−18</sup> [[metre|m]] and 10<sup>−17</sup> m (1 am and 10 am).

*1 am – sensitivity of the [[LIGO]] detector for [[gravitational wave]]s{{Citation needed|date=March 2018}}
*1 am – upper limit for the size of [[quark]]s and [[electron]]s{{Citation needed|date=March 2018}}

==10 attometres==
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−17</sup> [[metre|m]] and 10<sup>−16</sup> m (10 [[attometre|am]] and 100 am).

*10–100 am – range of the weak force<ref>{{cite web |author=Christman, J. |year=2001 |title=The Weak Interaction |website=Physnet |publisher=[[Michigan State University]] |url=http://physnet2.pa.msu.edu/home/modules/pdf_modules/m281.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110720004912/http://physnet2.pa.msu.edu/home/modules/pdf_modules/m281.pdf |archive-date=20 July 2011 |df=dmy-all}}</ref>
*86 am – charge radius of a [[Eta meson|Bottom eta meson]]<ref name=quarkonia>{{Cite journal|last1=Raya|first1=Khépani|last2=Bedolla|first2=Marco A.|last3=Cobos-Martínez|first3=J. J.|last4=Bashir|first4=Adnan|date=31 October 2017|title=Heavy quarkonia in a contact interaction and an algebraic model: mass spectrum, decay constants, charge radii and elastic and transition form factors|journal=Few-Body Systems|volume=59|issue=6|pages=16|url=https://ui.adsabs.harvard.edu/abs/2018FBS....59..133R/abstract|bibcode=2018FBS....59..133R|doi=10.1007/s00601-018-1455-y|arxiv=1711.00383|s2cid=254061694 }}</ref>

==100 attometres==
To help compare different [[orders of magnitude]], this section lists lengths between 10<sup>−16</sup> [[metre|m]] and 10<sup>−15</sup> m (100 [[attometre|am]] and 1 [[femtometre|fm]]).

*831 am – approximate proton radius<ref>{{cite journal|url=https://scientificamerican.com/article/how-big-is-the-proton-particle-size-puzzle-leaps-closer-to-resolution|title=How Big Is the Proton? Particle-Size Puzzle Leaps Closer to Resolution|last=Castelvecchi|first=Davide|journal=Nature |date=2019-11-11|volume=575 |issue=7782 |pages=269–270 |publisher=Scientific American|doi=10.1038/d41586-019-03432-4 |pmid=31719693 |bibcode=2019Natur.575..269C |access-date=3 July 2024|url-access=subscription}}</ref><ref>{{cite journal |doi= 10.1038/nature09250 |title= The size of the proton |first1=Randolf |last1=Pohl |first2=Aldo |last2=Antognini |first3=François |last3=Nez |first4=Fernando D. |last4=Amaro |first5=François |last5=Biraben |first6=João M. R. |last6=Cardoso |first7=Daniel S. |last7=Covita |first8=Andreas |last8=Dax |first9=Satish |last9=Dhawan |first10=Luis M. P. |last10=Fernandes |first11=Adolf |last11=Giesen |first12=Thomas |last12=Graf |first13=Theodor W. |last13=Hänsch |first14=Paul |last14=Indelicato |first15=Lucile |last15=Julien |first16=Cheng-Yang |last16=Kao |first17=Paul |last17=Knowles |first18=Eric-Olivier |last18=Le Bigot |first19=Yi-Wei |last19=Liu |first20=José A. M. |last20=Lopes |first21=Livia |last21=Ludhova |author22=Cristina M. B. Monteiro |first23=Françoise |last23=Mulhauser |first24=Tobias |last24=Nebel |first25=Paul |last25=Rabinowitz |display-authors =etal |date= 8 July 2010|journal=Nature |volume=466 |issue= 7303 |pages =213–216 |pmid= 20613837 |bibcode=2010Natur.466..213P|s2cid= 4424731 |url= https://rdcu.be/bYa2m |url-access=subscription }}</ref>

==1 femtometre (or 1 fermi)==

The ''{{vanchor|[[femtometre]]}}'' ([[SI]] symbol: ''{{vanchor|fm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;15</sup>&nbsp;[[metre]]s}}. 
In [[particle physics]], this unit is sometimes called a [[fermi (unit)|{{vanchor|fermi}}]], also with abbreviation "fm". To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−15</sup> [[metre|metre]]s and 10<sup>−14</sup> metres (1 femtometre and 10 fm).

*1 fm – diametre of a [[neutron]], approximate range-limit of the [[strong interaction|color force]] carried between [[quark]]s by [[gluon]]s<ref name=profmattstrassler/><ref name=Kolena_at_Duke/>
*1.5 fm – diametre of the [[cross section (physics)|scattering cross section]] of an 11 [[electron volt|MeV]] [[proton]] with a target proton<ref name="Nav"/>
*1.75 fm – the effective charge diametre of a [[proton]]<ref>{{cite web |url=https://physics.nist.gov/cgi-bin/cuu/Value?rp |website=The NIST Reference on Constants, Units, and Uncertainty |title=proton rms charge radius}}</ref>
*2.81794 fm – [[classical electron radius]]<ref>[[National Institute of Standards and Technology|NIST]]. [http://physics.nist.gov/cgi-bin/cuu/Value?re CODATA Value:    classical electron radius]. Retrieved 2009-02-10</ref>
*3 fm – approximate range-limit of the [[strong interaction|nuclear binding force]] mediated by [[meson]]s<ref name=profmattstrassler/><ref name=Kolena_at_Duke/>
*7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a [[orders of magnitude (energy)#1E-15|6]]{{Broken anchor|date=2024-05-26|bot=User:Cewbot/log/20201008/configuration|target_link=orders of magnitude (energy)#1E-15|reason= The anchor (1E-15) [[Special:Diff/383862119|has been deleted]].}} [[electron volt|MeV]] [[alpha particle]] over 140 degrees<ref name="Nav"/>

==10 femtometres==
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−14</sup> [[metre|m]] and 10<sup>−13</sup> m (10 [[femtometre|fm]] and 100 fm).

*1.75 to 15 fm – diametre range of the [[atomic nucleus]]{{citation needed|date=March 2021}}
*10 fm – the length of one side of a square whose area is one [[barn (unit)|barn]] (10<sup>−28</sup> m<sup>2</sup>), a unit of [[Cross section (physics)|target cross section]] used in [[nuclear physics]]
*30.8568 fm – 1 quectoparsec (10<sup>−30</sup> [[parsecs]])

==100 femtometres==
To help compare different [[orders of magnitude]], this section lists lengths between 10<sup>−13</sup> [[metre|m]] and 10<sup>−12</sup> m (100 [[femtometre|fm]] and 1 [[picometre|pm]]).

*570 fm – typical distance from the atomic nucleus of the two innermost electrons (electrons in the ''1s'' shell) in the [[uranium]] atom, the heaviest naturally-occurring atom

==1 picometre==

The ''{{vanchor|[[picometre]]}}'' ([[SI]] symbol: ''pm'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;12</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|{{gaps|1|000|000|000|000}}}}&nbsp;m&nbsp;{{=}}&nbsp;0.{{gaps|000|000|000|001}}&nbsp;m}}). 
To help compare different [[order of magnitude|orders of magnitude]] this section lists [[length]]s between 10<sup>−12</sup> and 10<sup>−11</sup> m (1 pm and 10 pm).

*1 pm – distance between [[atomic nuclei]] in a [[white dwarf]]{{Citation needed|date=March 2018}}
*1 pm – reference value of particle displacement in acoustics<ref>ISO 1683:2015</ref>
*2.4 pm – the [[Compton wavelength]] of an [[electron]]
*5 pm – shorter [[X-ray]] wavelengths (approx.)

==10 picometres==
To help compare different [[order of magnitude|orders of magnitude]] this section lists [[length]]s between 10<sup>−11</sup> and 10<sup>−10</sup> [[metre|m]] (10 pm and 100 pm).

*25 pm – approximate radius of a helium atom, the smallest neutral atom<ref name="webelhy">{{cite web |first=Mark |last=Winter |title=WebElements Periodic Table of the Elements / Hydrogen / radii |url=http://www.webelements.com/hydrogen/atom_sizes.html |year=2008 |accessdate=2008-12-06| archiveurl= https://web.archive.org/web/20081218213512/http://www.webelements.com/hydrogen/atom_sizes.html| archivedate= 18 December 2008 <!--Added by DASHBot-->}}</ref><ref name="webelhe">{{cite web |first=Mark |last=Winter |title=WebElements Periodic Table of the Elements / Helium / radii |url=http://www.webelements.com/helium/atom_sizes.html |year=2008 |accessdate=2008-12-06| archiveurl= https://web.archive.org/web/20081219030040/http://www.webelements.com/helium/atom_sizes.html| archivedate= 19 December 2008 <!--Added by DASHBot-->}}</ref>
*30.8568 pm – 1 rontoparsec 
*50 pm – radius of a hydrogen atom
*50 pm – [[bohr radius]]: approximate radius of a hydrogen atom
*~50 pm – best resolution of a [[high-resolution transmission electron microscopy|high-resolution transmission electron microscope]]
*60 pm – radius of a carbon atom
*93 pm – length of a [[diatomic carbon]] molecule
*96 pm – H–O bond length in a [[water]] molecule

==100 picometres==
To help compare different [[order of magnitude|orders of magnitude]] this section lists [[length]]s between 10<sup>−10</sup> and 10<sup>−9</sup> [[metre|m]] (100&nbsp;pm and 1&nbsp;nm; 1&nbsp;[[angstrom|Å]] and 10&nbsp;Å).

*100 pm – 1 [[ångström]]
*100 pm – [[covalent radius]] of [[sulfur]] atom<ref>{{cite web |first=Mark |last=Winter |title=WebElements Periodic Table of the Elements / Sulfur / Radii |url=http://www.webelements.com/sulfur/atom_sizes.html |year=2008 |accessdate=2008-12-06| archiveurl= https://web.archive.org/web/20081211084435/http://www.webelements.com/sulfur/atom_sizes.html| archivedate= 11 December 2008 <!--Added by DASHBot-->}}</ref>
*120 pm – [[van der Waals radius]] of a neutral [[hydrogen]] atom<ref>{{cite web |first=Mark |last=Winter |title=WebElements Periodic Table of the Elements / Periodicity / Van der Waals radius / periodicity |url=http://www.webelements.com/periodicity/van_der_waals_radius/ |year=2008 |accessdate=2008-12-06| archiveurl= https://web.archive.org/web/20081219170602/http://www.webelements.com/periodicity/van_der_waals_radius/| archivedate= 19 December 2008 <!--Added by DASHBot-->}}</ref>
*120 pm – radius of a gold atom
*126 pm – covalent radius of [[ruthenium]] atom
*135 pm – covalent radius of [[technetium]] atom
*150 pm – length of a typical [[covalent bond]] ([[Carbon|C]]–C)
*153 pm – covalent radius of [[silver]] atom
*155 pm – covalent radius of [[zirconium]] atom
*175 pm – covalent radius of [[thulium]] atom
*200 pm – highest resolution of a typical [[electron microscope]]<ref>{{cite web|title=Resolution of an Electron Microscope |url=http://hypertextbook.com/facts/2000/IlyaSherman.shtml |archiveurl=https://web.archive.org/web/20090316071444/http://hypertextbook.com/facts/2000/IlyaSherman.shtml |archivedate=2009-03-16 |url-status=live |accessdate=2009-04-25 }}</ref>
*225 pm – covalent radius of [[caesium]] atom
*280 pm – average size of the [[water]] molecule
*298 pm – radius of a [[caesium]] atom, [[atomic radius#Calculated atomic radii|calculated to be]] the largest atomic radius<!--YES REALLY NOT FRANCIUM, RELATIVISTIC EFFECTS MAKE IT SMALLER; figures at [[Covalent radius]] show this-->
*340 pm – thickness of single layer [[graphene]]
*356.68 pm – width of [[diamond]] [[unit cell]]
*403 pm – width of [[lithium fluoride]] unit cell
*500 pm – Width of [[protein]] [[alpha helix|α helix]]
*543 pm – silicon lattice spacing
*560 pm – width of [[sodium chloride]] unit cell
*700 pm – width of [[glucose]] molecule
*700 pm – diametre of a [[buckyball]]<ref>{{Cite web|url=http://www.chm.bris.ac.uk/motm/buckyball/c60a.htm|title=Buckminsterfullerene: Molecule of the Month|website=www.chm.bris.ac.uk|access-date=21 April 2019}}</ref>
*780 pm – mean width of [[quartz]] unit cell
*820 pm – mean width of [[ice]] unit cell
*900 pm – mean width of [[coesite]] unit cell

==1 nanometre==

The ''{{vanchor|[[nanometre]]}}'' ([[SI]] symbol: ''{{vanchor|nm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;9</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|{{gaps|1|000|000|000}}}}&nbsp;m&nbsp;{{=}}&nbsp;0.{{gaps|000|000|001}}&nbsp;m}}). 
To help compare different [[order of magnitude|orders of magnitude]], this section lists lengths between 10<sup>−9</sup> and 10<sup>−8</sup> m (1&nbsp;nm and 10&nbsp;nm).

*1&nbsp;nm – diametre of a [[carbon nanotube]]
*1&nbsp;nm – roughly the length of a [[sucrose]] molecule, calculated by [[Albert Einstein]]
*2.3&nbsp;nm – length of a [[phospholipid]]
*2.3&nbsp;nm – smallest [[Gate (transistor)|gate]] oxide thickness in [[microprocessor]]s
*3&nbsp;nm – width of a [[DNA]] helix
*3&nbsp;nm – [[flying height]] of the [[disk read-and-write head|head]] of a [[hard disk]]
*3&nbsp;nm – the [[3 nm process|average half-pitch of a memory cell manufactured circa 2022]]
*3.4&nbsp;nm – length of a DNA [[turn (biochemistry)|turn]] (10 [[base pair|bp]])
*3.8&nbsp;nm – size of an [[albumin]] molecule
*5&nbsp;nm – size of the gate length of a 16&nbsp;nm processor
*5&nbsp;nm – the [[5 nm process|average half-pitch of a memory cell manufactured circa 2019–2020]]
*6&nbsp;nm – length of a [[phospholipid]] bilayer
*6–10&nbsp;nm – thickness of cell membrane
*6.8&nbsp;nm – width of a [[haemoglobin]] molecule
*7&nbsp;nm – diametre of [[Microfilament|actin filaments]]
*7&nbsp;nm – the [[7 nm process|average half-pitch of a memory cell manufactured circa 2018]]
*10&nbsp;nm – thickness of [[cell wall]] in [[Gram staining|Gram]]-negative [[bacteria]]

==10 nanometres==
[[Image:Comparison semiconductor process nodes.svg|thumb|Comparison of sizes of semiconductor manufacturing process nodes with some microscopic objects and visible light wavelengths. At this scale, the [[Hair's breadth|width of a human hair]] is about 10 times that of the image.<ref>{{cite book|title=Industrial metrology|url=https://archive.org/details/industrialmetrol00mphi|url-access=limited|first=Graham T.|last=Smith|pages=[https://archive.org/details/industrialmetrol00mphi/page/n256 253]|publisher= Springer|year=2002|isbn=978-1-85233-507-6}}</ref>]]
To help compare different [[order of magnitude|orders of magnitude]] this section lists [[length]]s between 10<sup>−8</sup> and 10<sup>−7</sup> [[metre|m]] (10&nbsp;nm and 100&nbsp;nm).

*10&nbsp;nm Shortest [[extreme ultraviolet]] wavelength or longest [[X-ray]] wavelength<ref name="em-spectrum">[http://pharmaxchange.info/press/2011/08/introduction-to-the-electromagnetic-spectrum-and-spectroscopy/ Introduction to the Electromagnetic Spectrum and Spectroscopy]</ref>
*10&nbsp;nm – the average length of a [[nanowire]]
*10&nbsp;nm – lower size of tobacco smoke<ref name="Ann">Annis, Patty J. October 1991. [[Kansas State University]]. ''Fine Particle POLLUTION''. Figure 1. (tobacco smoke: 10 to {{val|1000|u=nm}}; virus particles: 3 to 50&nbsp;nm; bacteria: 30 to {{val|30000|u=nm}}; cooking oil smoke: 30 to {{val|30000|u=nm}}; wood smoke: 7 to {{val|3000|u=nm}})</ref>
*10&nbsp;nm – the [[10 nm process|average half-pitch of a memory cell manufactured circa 2016]] [[32 nm process|–]]2017
*13&nbsp;nm – the length of the wavelength that is used for [[EUV lithography]]
*14&nbsp;nm – length of a [[porcine circovirus]]
*14&nbsp;nm – the [[14 nm process|average half-pitch of a memory cell manufactured circa 2013]]
*15&nbsp;nm – length of an antibody
*18&nbsp;nm – diametre of [[tobacco mosaic virus]]<ref name="isbn0-7167-1843-X">{{cite book|title=Biochemistry|publisher=W.H. Freeman|year=1988|isbn=978-0-7167-1843-7|location=San Francisco|author=Stryer, Lubert|url-access=registration|url=https://archive.org/details/biochemistry3rdedi00stry}}</ref> {{citation needed span|text=(Generally, [[virus (biology)|viruses]] range in size from 20&nbsp;nm to 450&nbsp;nm.)|date=February 2009}}
*20&nbsp;nm – length of a [[nanobe]], could be one of the smallest forms of life
*20–80&nbsp;nm – thickness of [[cell wall]] in [[Gram-positive bacteria]]<ref>{{cite web|url=http://www.microbiologytext.com/index.php?module=Book&func=displayarticle&art_id=60|title=Through the Microscope|website=www.microbiologytext.com|access-date=21 May 2017|archive-date=12 June 2016|archive-url=https://web.archive.org/web/20160612050607/http://www.microbiologytext.com/index.php?module=book&func=displayarticle&art_id=60|url-status=dead}}</ref>
*20&nbsp;nm – thickness of [[bacteria]]l [[flagellum]]<ref>{{cite journal |vauthors=Kojima S, Blair D |title=The Bacterial Flagellar Motor: Structure and Function of a Complex Molecular Machine |journal=Int Rev Cytol |volume=233 |pages=93–134 |year=2004|pmid=15037363 |doi=10.1016/S0074-7696(04)33003-2 |series=International Review of Cytology |isbn=978-0-12-364637-8}}</ref>
*22&nbsp;nm – the [[22 nm process|average half-pitch of a memory cell manufactured circa 2011–2012]]
*22&nbsp;nm – smallest feature size of production [[microprocessor]]s in September 2009<ref name="Intel">{{cite web|url=https://phys.org/news/2009-09-law-intel.html|title=Moore's Law Marches on at Intel|publisher=Physorg.com|access-date=1 September 2018}}</ref>
*25&nbsp;nm – diametre of a [[microtubule]]
*30&nbsp;nm – lower size of cooking oil smoke
*30.8568&nbsp;nm – 1 yoctoparsec
*32&nbsp;nm – the [[32 nm process|average half-pitch of a memory cell manufactured circa 2009–2010]]
*40&nbsp;nm – extreme [[ultraviolet]] wavelength
*45&nbsp;nm – the [[45 nm process|average half-pitch of a memory cell manufactured circa 2007–2008]]
*50&nbsp;nm – upper size for airborne [[virus]] particles
*50&nbsp;nm – [[flying height]] of the [[disk read-and-write head|head]] of a [[hard disk]]<ref>{{cite web|url=https://www.helpwithpcs.com/hardware/hard-drive-basics.php|title=Hard drive basics – Capacities, RPM speeds, interfaces and mechanics|website=www.helpwithpcs.com}}</ref>
*65&nbsp;nm – the [[65 nm process|average half-pitch of a memory cell manufactured circa 2005–2006]]
*58&nbsp;nm – height of a [[T7 bacteriophage]]
*90&nbsp;nm – [[HIV/AIDS|human immunodeficiency virus (HIV)]] (generally, [[virus]]es range in size from 20&nbsp;nm to 450&nbsp;nm)
*90&nbsp;nm – the [[90 nm process|average half-pitch of a memory cell manufactured circa 2002–2003]]
*100&nbsp;nm – Length of a [[mesoporous silica]] nanoparticle

==100 nanometres==
[[File:Comparison semiconductor process nodes.svg|thumb|upright=1.5|Comparison of sizes of semiconductor manufacturing process nodes with some microscopic objects and visible light wavelengths. At this scale, the [[hair's breadth|width of a human hair]] is about 10 times that of the image.<ref>{{cite book|title=Industrial metrology|url=https://archive.org/details/industrialmetrol00mphi|url-access=limited|first=Graham T.|last=Smith|page=[https://archive.org/details/industrialmetrol00mphi/page/n256 253]|publisher=Springer|year=2002|isbn=978-1-85233-507-6}}</ref>]]

To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−7</sup> and 10<sup>−6</sup> [[metre|m]] (100 [[nanometre|nm]] and 1&nbsp;[[micrometre|μm]]).

*100&nbsp;nm – greatest particle size that can fit through a [[surgical mask]]<ref name=t2>{{Cite journal |doi = 10.1080/02786820802626355|title = Electrospray versus Nebulization for Aerosolization and Filter Testing with Bacteriophage Particles|journal = Aerosol Science and Technology|volume = 43|issue = 4|pages = 298–304|year = 2009|last1 = Eninger|first1 = Robert M.|last2 = Hogan|first2 = Christopher J.|last3 = Biswas|first3 = Pratim|last4 = Adhikari|first4 = Atin|last5 = Reponen|first5 = Tiina|last6 = Grinshpun|first6 = Sergey A.|bibcode = 2009AerST..43..298E|s2cid = 93465533}}</ref>
*100&nbsp;nm – 90% of particles in wood [[smoke]] are smaller than this.{{citation needed|date=December 2008}}
*120&nbsp;nm – greatest particle size that can fit through a [[ULPA]] filter<ref>{{cite web|url=https://www3.epa.gov/ttncatc1/dir1/ff-hepa.pdf|title=Air Pollution [Control] Technology Fact Sheet|publisher=United States Environmental Protection Agency|access-date=3 July 2024}}</ref>
*120&nbsp;nm – diametre of a [[human immunodeficiency virus]] (HIV)<ref>{{cite book|url=https://books.google.com/books?id=51ozlZRBvQwC&pg=SL24-PA111|title=Textbook Of Pharmacology|last=Seth|date=18 November 2009|publisher=Elsevier India|via=Google Books|isbn=9788131211588}}</ref>
*120&nbsp;nm – approximate diametre of [[Severe acute respiratory syndrome coronavirus 2|SARS-CoV-2]]<ref>{{Cite web|url=https://www.pptaglobal.org/media-and-information/ppta-statements/1055-2019-novel-coronavirus-2019-ncov-and-plasma-protein-therapies|title=New Coronavirus (SARS-CoV-2) and the Safety Margins of Plasma Protein Therapies – Plasma Protein Therapeutics Association (PPTA)|access-date=30 May 2020|archive-date=2 June 2020|archive-url=https://web.archive.org/web/20200602211857/https://www.pptaglobal.org/media-and-information/ppta-statements/1055-2019-novel-coronavirus-2019-ncov-and-plasma-protein-therapies|url-status=dead}}</ref>
*125&nbsp;nm – standard depth of pits on [[compact disc]]s (width: 500&nbsp;nm, length: 850&nbsp;nm to 3.5&nbsp;μm)
*180&nbsp;nm – typical length of the [[rabies|rabies virus]]
*200&nbsp;nm – typical size of a ''[[Mycoplasma]]'' bacterium, among the smallest bacteria
*300&nbsp;nm – greatest particle size that can fit through a [[HEPA]] (high efficiency particulate air) filter (N100 removes up to 99.97% at 300 nm, N95 removes up to 95% at 300 nm)<ref>{{cite web|url=https://cdc.gov/niosh/docs/96-101/default.html|title=NIOSH Guide to the Selection and Use of Particulate Respirators|year=1996|publisher=Centers for Disease Control and Prevention|access-date=3 July 2024}}</ref>
*300–400&nbsp;nm – near [[ultraviolet]] wavelength
*400–420&nbsp;nm – wavelength of [[violet (color)|violet]] light (see [[Color]] and [[Visible spectrum]])
*420–440&nbsp;nm – wavelength of [[indigo]] light 
*440–500&nbsp;nm – wavelength of [[blue]] light
*500–520&nbsp;nm – wavelength of [[cyan]] light 
*520–565&nbsp;nm – wavelength of [[green]] light 
*565–590&nbsp;nm – wavelength of [[yellow]] light 
*590–625&nbsp;nm – wavelength of [[orange (colour)|orange]] light 
*625–700&nbsp;nm – wavelength of [[red]] light 
*700–1.4 μm – wavelength of [[near-infrared]] radiation

==1 micrometre (or 1 micron)==
<!-- Linked to from Microplastics -->
[[File:Loxoceles reclusa iconized thread.png|thumb|upright|The silk for a spider's web is {{cvt|5–7|μm}} wide.]]

The ''{{vanchor|[[micrometre]]}}'' ([[SI]] symbol: ''{{vanchor|μm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;6</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|{{gaps|1|000|000}}}}&nbsp;m&nbsp;{{=}}&nbsp;0.{{gaps|000|001}}&nbsp;m}}). 
To help compare different [[orders of magnitude]], this section lists some items with lengths between 10<sup>−6</sup> and 10<sup>−5</sup> m (between 1 and 10 [[micrometre|micrometre]]s, or μm).

*~0.7–300 μm – wavelength of [[infrared radiation]]
*1 μm – the side of a [[square (geometry)|square]] of area [[orders of magnitude (area)|10<sup>−12</sup> m<sup>2</sup>]]
*1 μm – edge of [[cube (geometry)|cube]] of volume [[orders of magnitude (volume)|10<sup>−18</sup> m<sup>3</sup>]] (1&nbsp;fL)
*1–10 μm – diametre of a typical [[bacterium]]{{citation needed|date=June 2016}}
*1 μm – length of a [[lysosome]]
*1–2 μm – [[anthrax disease|anthrax]] spore<ref>{{cite journal|vauthors=Spencer RC|title=Bacillus anthracis|journal=Journal of Clinical Pathology|volume=56|issue=3|pages=182–7|date=March 2003|pmid=12610093|pmc=1769905|doi=10.1136/jcp.56.3.182}}</ref>
*2 μm – length of an average [[E. coli]] bacteria
*3–4 μm – size of a typical [[yeast]] cell<ref name=Walker>{{cite journal|vauthors=Walker K, Skelton H, Smith K|title=Cutaneous lesions showing giant yeast forms of Blastomyces dermatitidis|journal=Journal of Cutaneous Pathology|volume=29|issue=10|pages=616–8|date=November 2002|pmid=12453301|doi=10.1034/j.1600-0560.2002.291009.x|s2cid=39904013}}</ref>
*5 μm – length of a typical human [[spermatozoon]]'s head<ref>{{cite journal|last=Smith|first=D.J.|title=Human sperm accumulation near surfaces: a simulation study|journal=Journal of Fluid Mechanics|year=2009|volume=621|page=295|doi=10.1017/S0022112008004953|url=http://eprints.maths.ox.ac.uk/860/1/human_sperm.pdf|access-date=20 May 2012|bibcode=2009JFM...621..289S|s2cid=3942426|archive-url=https://web.archive.org/web/20131106030353/http://eprints.maths.ox.ac.uk/860/1/human_sperm.pdf|archive-date=6 November 2013|url-status=dead}}</ref>
*6 μm – thickness of the tape in a 120-minute (C120) [[compact cassette]]<ref>{{cite web|url=http://nactape.com/anablog/glossary|title=NAC Audio Cassette Glossary – Cassetro|website=nactape.com|language=en-US|access-date=16 March 2018}}</ref>
*7 μm – diametre of the [[cell nucleus|nucleus]] of a typical eukaryotic [[cell (biology)|cell]]{{citation needed|date=June 2016}}
*about 7 μm – diametre of human [[red blood cell]]s<ref name="dnaftb">{{cite web|url=http://www.dnaftb.org/dnaftb/6/concept/index.html|title=Genes are real things :: DNA from the Beginning|website=www.dnaftb.org}}</ref>
*3–8 μm – width of strand of [[spider silk|spider web silk]]<ref>{{cite web|first=Gordon|last=Ramel|title=Spider Silk|url=http://www.earthlife.net/chelicerata/silk.html|quote=garden spider silk has a diametre of about 0.003 mm ... Dragline silk (about 0.00032 inch (0.008 mm) in Nephila)|access-date=4 December 2008|archive-url=https://web.archive.org/web/20081204080140/http://www.earthlife.net/chelicerata/silk.html|archive-date=4 December 2008 |url-status=live}}</ref>
*5–10 μm – width of a [[chloroplast]]<ref>{{cite book|author1=Wise, R.R.|author2=Hoober, J.K.|year=2007|title=The Structure and Function of Plastids|publisher=Springer|isbn=978-1-4020-6570-5|url=https://books.google.com/books?id=FKeCVPbJ3asC|page=14}}</ref>
*8–11 μm – size of a ground-level fog or mist droplet<ref>{{cite report|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940028559.pdf|title=Drop Size Distributions and Related Properties of Fog for Five Locations Measured From Aircraft|last=Zak|first=J. Allen|date=April 1994|publisher=[[NASA]] – [[Langley Research Center]]|location=Hampton, VA|docket=4585}}</ref><ref group="note">But not [[cloud]] or high-level fog droplets; droplet size increases with altitude. For a contradictory study indicating larger drop sizes even in ground fog, see {{cite journal|last=Eldridge|first=Ralph G.|date=October 1961|title=A Few Fog Drop-Size Distributions|journal=Journal of Meteorology|volume=18|issue=5|pages=671–6|doi=10.1175/1520-0469(1961)018<0671:AFFDSD>2.0.CO;2|bibcode=1961JAtS...18..671E|doi-access=free}}</ref>
*7–12 μm – the diametre of human [[white blood cell]]s
*8–10 μm – the diametre of human [[macrophage]]s

==10 micrometres==
[[File:FogParticlesHighSpeed.jpg|thumb|Fog particles are around {{cvt|10–50|μm}} long.]]
To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−5</sup> [[metre|m]] and 10<sup>−4</sup> m (10 [[micrometre|μm]] and 100&nbsp;μm).

*10 μm – width of [[cotton]] fibre<ref name="ISTAG">{{cite web|author=IST – Innovative Sintering Technologies Ltd.|title=Fibreshape applications|url=http://www.istag.ch/fibres/applications.html|quote=Histogram of cotton thickness|access-date=4 December 2008}}</ref>
*10 μm – [[Engineering tolerance|tolerance]] of a [[Lego]] brick<ref name="Companyprofile">{{cite web|url=http://cache.lego.com/upload/contentTemplating/AboutUsFactsAndFiguresContent/otherfiles/download98E142631E71927FDD52304C1C0F1685.pdf|title=Company Profile, page 20|date=2010|publisher=The Lego Group|url-status=dead|archive-url=https://web.archive.org/web/20121209100137/http://cache.lego.com/upload/contentTemplating/AboutUsFactsAndFiguresContent/otherfiles/download98E142631E71927FDD52304C1C0F1685.pdf|archive-date=9 December 2012}}</ref>
*10 μm – [[transistor]] width of the [[Intel 4004]], the world's first commercial [[microprocessor]]
*10 μm – mean longest dimension of a human [[red blood cell]]{{citation needed|date=September 2014}}
*5–20 μm – [[dust mite]] excreta<ref>{{cite book|first=Morton|last=Lippmann|title=Environmental Toxicants: Human Exposures and Their Health Effects|publisher=John Wiley and Sons|year=2000|isbn=978-0-471-29298-2|url=https://books.google.com/books?id=7eCXlRbCeGAC|page=453|quote=20 μm .. 5 μm|access-date=4 December 2008}}</ref>
*10.6 μm – wavelength of light emitted by a [[carbon dioxide laser]]
*15 μm – width of [[silk]] fibre{{citation needed|date=September 2014}}
*17 μm – minimum width of a strand of human hair<ref name="Physics Factbook"/>
*17.6 μm – one [[twip]], a unit of length in typography
*10 to 55 μm – width of [[wool]] fibre<ref name="ISTAG"/>
*25.4 μm – 1/1,000&nbsp;inch, commonly referred to as 1 [[thou (unit of length)|mil]] in the U.S. and 1 [[thou (unit of length)|thou]] in the U.K.
*30 μm – length of a human [[skin cell]]
*30.8568 μm – 1 zeptoparsec
*50 μm – typical length of ''[[Euglena gracilis]]'', a flagellate protist<ref>{{cite journal|last=Rossi|first=Massimiliano|date=2017-11-27|title=Kinematics of flagellar swimming in ''Euglena gracilis'': Helical trajectories and flagellar shapes|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=114 |issue=50 |pages=13085–13090 |doi=10.1073/pnas.1708064114 |doi-access=free |pmid=29180429 |pmc=5740643 |bibcode=2017PNAS..11413085R |hdl=11384/84166 |hdl-access=free }}</ref>
*50 μm – typical length of a human [[liver]] cell, an average-sized body cell{{citation needed|date=September 2014}}
*50 μm – length of a [[silt]] particle
*60 μm – length of a [[sperm cell]]
*78&nbsp;μm — width of a pixel on the display of the iPhone 4, marketed as [[Retina Display]]<ref>{{cite web|title=Apple – iPhone 4S – See everything clearly with the Retina display|url=https://www.apple.com/iphone/features/retina-display.html|work=Apple Inc. Official Website|publisher=Apple Inc.|accessdate=10 March 2012}}</ref> 
*70 to 180 μm – thickness of paper

==100 micrometres==
[[File:Paramecium.jpg|thumb|A [[paramecium]] is around {{cvt|300| μm}} long.]]

To help compare different [[orders of magnitude]], this section lists [[length]]s between 10<sup>−4</sup> [[metre|m]] and 10<sup>−3</sup> m (100&nbsp;[[micrometre|μm]] and 1&nbsp;[[millimetre|mm]]). The term ''myriometre'' (abbr. mom, equivalent to 100 micrometres; frequently confused with the ''[[#Myriametre|myriametre]]'', 10 kilometres)<ref>{{cite book|url=https://books.google.com/books?id=XnRVDwAAQBAJ&pg=PA204|first=Jan|last=Gyllenbok|title=Encyclopedia of Historical Metrology, Weights, and Measures|publisher=Birkhäuser|year=2018|isbn=9783319575988}}</ref> is deprecated; the decimal metric prefix [[myria-|myrio-]]<ref name="fr"/> is obsolete<ref name="Procès-Verbaux_1935"/><ref name="Roberts_1975"/><ref name="Judson_1976"/> and was not included among the [[SI prefixes|prefixes]] when the [[International System of Units]] was introduced in 1960.

*100 μm – 1/10 of a millimetre
*100 μm – 0.00394&nbsp;inches
*100 μm – smallest distance that can be seen with the [[naked eye]]
*100 μm – average diametre of a strand of [[human hair]]<ref name="Physics Factbook"/>
*100 μm – thickness of a coat of [[paint]]
*100 μm – length of a [[dust]] particle
*120 μm – the [[geometric mean]] of the [[Planck length]] and the diametre of the [[observable universe]]: {{radic|8.8 × 10<sup>26</sup> m × 1.6 × 10<sup>−35</sup> m}}
*120 μm – diametre of a [[human]] [[ovum]]
*170&nbsp;μm – length of the largest mammalian [[sperm cell]] (rat)<ref>{{cite web|url = http://www2.oakland.edu/biology/lindemann/spermfacts.htm |title = Sperm Facts|website = Dr. Charles Lindmann's Lab|publisher = Oakland University|last = Lindemann|first = Charles}}</ref>
*170 μm – length of the largest [[sperm cell]] in nature, belonging to the ''[[Drosophila bifurca]]'' fruit fly<ref>{{cite web|url=https://files.oakland.edu/users/lindeman/web/spermfacts.htm|title=Dr. Charles Lindemann's Lab: Sperm Facts|first=Kim|last=Popiolek|publisher=Oakland University}}</ref><ref>{{cite web|last1=Santoso|first1=Alex|title=World's Biggest Sperm Belongs to a Tiny Fly|url=https://www.neatorama.com/2006/06/17/worlds-biggest-sperm-belongs-to-a-tiny-fly/|website=Neatorama|date=17 June 2006}}</ref>
*181 μm – maximum width of a strand of human hair<ref name="Physics Factbook"/>
*100–400 μm – length of [[Demodex mite]]s living in human [[hair follicle]]s
*175–200 μm – typical thickness of a [[solar cell]].
*200 μm – typical length of ''[[Paramecium|Paramecium caudatum]]'', a ciliate protist
*200 μm – nominal width of the smallest commonly available mechanical pencil lead (0.2&nbsp;mm)
*250–300 μm – length of a [[dust mite]]<ref>{{cite web|archiveurl = https://web.archive.org/web/20011102080548/http://ohioline.osu.edu/hyg-fact/2000/2157.html|title = House Dust Mites|id= HYG-2157-97|last = Lyon|first = William F.|website = Ohio State University Extension| url = http://ohioline.osu.edu/hyg-fact/2000/2157.html|url-status = dead|archivedate= 2 November 2001}}</ref>
*340 μm – length of a [[pixel]] on a 17-inch monitor with a resolution of 1024×768
*500 μm – typical length of ''[[Amoeba proteus]]'', an amoeboid protist
*500 μm – [[Microelectromechanical systems|MEMS]] micro-engine<ref>{{cite web|url=https://sandia.gov/app/uploads/sites/145/2021/11/4_5Designing.pdf|title=Designing and Operating Electrostatically Driven Microengines|last=Rodgers|first=Steven|publisher=Sandia National Laboratory|access-date=3 July 2024}}</ref>
*500 μm – average length of a grain of [[sand]]
*500 μm – average length of a grain of [[salt]]
*500 μm – average length of a grain of [[sugar]]
*560 μm – thickness of the central area of a human [[cornea]]<ref name="ReferenceA"/>
*750 μm – diametre of a [[Thiomargarita namibiensis]], the largest bacteria known<ref>{{cite news|url=http://www.cnn.com/NATURE/9904/15/biggest.bacteria/|title=CNN – Scientists discover biggest bacteria ever – April 15, 1999|website=www.cnn.com|access-date=20 May 2017}}</ref>
*760 μm – thickness of an [[ISO/IEC 7810|identification card]]

==1 millimetre==
[[File:Fire ants 01.jpg|thumb|upright|An average [[fire ant|red ant]] is about {{cvt|5| mm}} long.]]
{{Redirect|1mm|the Perfume song|Level3 (Perfume album)|the measure|millimetre}}

The ''{{vanchor|[[millimetre]]}}'' ([[SI]] symbol: ''{{vanchor|mm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;3</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|{{gaps|1|000}}}}&nbsp;m&nbsp;{{=}}&nbsp;0.001&nbsp;m}}). 
To help compare different [[orders of magnitude]], this section lists lengths between 10<sup>−3</sup> m and 10<sup>−2</sup> m (1&nbsp;mm and 1&nbsp;cm).

*1.0&nbsp;mm – 1/1,000 of a metre
*1.0&nbsp;mm – 0.03937 [[inch]]es or 5/127 (exactly)
*1.0&nbsp;mm – side of a [[square (geometry)|square]] of area [[1 E-6 m²|1 mm²]]
*1.0&nbsp;mm – diametre of a pinhead
*1.5&nbsp;mm – average length of a flea<ref name="BugGuide"/>
*2.54&nbsp;mm – distance between pins on old [[dual in-line package]] (DIP) electronic components
*5&nbsp;mm – length of an average red ant
*5&nbsp;mm – diametre of an average grain of rice
*[[5.56×45mm NATO]] – standard ammunition size
*6&nbsp;mm – approximate width of a pencil
*7&nbsp;mm – length of a ''[[Paedophryne amauensis]]'', the smallest-known vertebrate<ref>{{cite news|url=https://news.nationalgeographic.com/news/2012/01/120111-smallest-frogs-vertebrates-new-species-science-animals/|archive-url=https://web.archive.org/web/20120113072722/http://news.nationalgeographic.com/news/2012/01/120111-smallest-frogs-vertebrates-new-species-science-animals/|url-status=dead|archive-date=13 January 2012|title=World's Smallest Frog Found—Fly-Size Beast Is Tiniest Vertebrate|date=13 January 2017|access-date=20 May 2017}}</ref>
*7.1&nbsp;mm – length of a sunflower seed
*[[7.62×51mm NATO]] – common military ammunition size<ref>[http://www.dtic.mil/ndia/2008Intl/Arvidsson.pdf NATO Infantry Weapons Standardization, Per G. Arvidsson, ChairmanWeapons & Sensors Working GroupLand Capability Group 1 – Dismounted Soldier NATO Army Armaments Group] {{webarchive|url=https://web.archive.org/web/20121201183951/http://www.dtic.mil/ndia/2008Intl/Arvidsson.pdf|date=1 December 2012}} Accessed 29 April 2014</ref>
*8&nbsp;mm – width of old-format home movie film
*8&nbsp;mm – length of a ''[[Paedocypris progenetica]]'', the smallest-known fish<ref>{{cite news|url=https://www.newscientist.com/article/mg18925363-000-worlds-smallest-vertebrate-has-a-big-secret/|title=World's smallest vertebrate has a big secret|work=New Scientist|access-date=20 May 2017|language=en-US}}</ref>

==1 centimetre==
[[File:Fingernail label (enwiki).jpg|thumb|An average human [[fingernail]] is {{cvt|1| cm}} wide]]
{{redirect|10 mm|firearms cartridges|10 mm calibre}}

The ''{{vanchor|[[centimetre]]}}'' ([[SI]] symbol: ''{{vanchor|cm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;2</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|100}}&nbsp;m&nbsp;{{=}}&nbsp;0.01&nbsp;m}}). 
To help compare different [[orders of magnitude]], this section lists lengths between 10<sup>−2</sup> m and 10<sup>−1</sup> m (1&nbsp;cm and 1&nbsp;dm).

*1&nbsp;cm – 10 [[millimetres|millimetres]]
*1&nbsp;cm – 0.39 [[inch]]es
*1&nbsp;cm – edge of a [[square]] of area [[orders of magnitude (area)|1 cm<sup>2</sup>]]
*1&nbsp;cm – edge of a [[cube (geometry)|cube]] of volume [[orders of magnitude (volume)|1 mL]]
*1&nbsp;cm – length of a coffee bean
*1&nbsp;cm – approximate width of average fingernail
*1.2&nbsp;cm – length of a bee
*1.2&nbsp;cm – diametre of a die
*1.5&nbsp;cm – length of a very large mosquito
*1.6&nbsp;cm – length of a Jaragua Sphaero, a very small reptile
*1.7&nbsp;cm – length of a Thorius arboreus, the smallest salamander<ref>{{cite news|url=https://kids.mongabay.com/animals/smallest/smallest-salamander.html|title=The Smallest Salamander|work=Mongabay.com|access-date=20 May 2017|last=Lindstrom|first=Hannah}}</ref>
*2&nbsp;cm – approximate width of an adult human finger
*2.54&nbsp;cm – 1 inch
*3.08568&nbsp;cm – 1 [[attoparsec]]
*3.4&nbsp;cm – length of a quail egg<ref>{{cite news|url=https://www.backyardchickens.com/threads/comparing-quail-eggs.410632/|title=Comparing quail eggs|work=BackYard Chickens|access-date=20 May 2017|language=en-US}}</ref>
*3.5&nbsp;cm – width of film commonly used in motion pictures and still photography
*3.78&nbsp;cm – amount of distance the Moon moves away from Earth each year<ref>{{Cite news|date=1 February 2011|title=Why the Moon is getting further away from Earth|language=en-GB|work=BBC News|url=https://www.bbc.com/news/science-environment-12311119|access-date=5 November 2021}}</ref>
*4.3&nbsp;cm – minimum diametre of a golf ball<ref>{{cite web|title=USGA: Guide to the Rules on Clubs and Balls|url=http://www.usga.org/Rule-Books/Rules-on-Clubs-and-Balls/Appendix-III-%e2%80%93-The-Ball/|publisher=USGA|access-date=30 September 2011}}</ref>
*5&nbsp;cm – usual diametre of a chicken egg
*5&nbsp;cm – height of a hummingbird, the smallest-known bird
*5.08&nbsp;cm – 2 [[inch]]es,
*5.5 × 5.5 × 5.5&nbsp;cm – dimensions of a 3x3x3 Rubik's cube
*6.1&nbsp;cm – average height of an apple
*7.3–7.5&nbsp;cm – diametre of a baseball<!-- Calculated from requirement that the circumference be 9 to 9.25 inches: 9*2.54/pi = 7.3e-2m. 9.25*2.54/pi = 7.5e-2m --><ref name="Official Rules"/>
*8.6&nbsp;cm × 5.4&nbsp;cm – dimensions of a standard credit card (also called CR80)<ref>{{cite web|url=https://cardlogix.com/glossary/cr80|title=CR80 Card Specification|publisher=CardLogix Corporation|access-date=3 July 2024}}</ref><ref>{{cite web |url=http://www.dimensionsguide.com/credit-card-dimensions/ |title=Credit Card Dimensions |accessdate=2011-09-30 }}</ref>
*9&nbsp;cm – length of a speckled padloper, the smallest-known turtle

==1 decimetre==
{{Redirect|10cm|the band|10cm (band)}}

[[File:Foot_on_white_background.jpg|thumb|An adult human foot is about {{cvt|28| cm}} long.]]

The ''{{vanchor|[[decimetre]]}}'' ([[SI]] symbol: ''{{vanchor|dm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{nowrap|1=10<sup>&minus;1</sup>&nbsp;[[metre]]s}} ({{nowrap|1={{sfrac|10}}&nbsp;m&nbsp;{{=}}&nbsp;0.1&nbsp;m}}). 
To help compare different [[orders of magnitude]], this section lists lengths between 10 [[centimetre|centimetre]]s and 100 centimetres (10<sup>−1</sup> metre and 1&nbsp;metre).

===Conversions===
10 centimetres (abbreviated to 10&nbsp;cm) is equal to:

*1 [[decimetre|decimetre]] (dm), a term not in common use (1 [[litre|L]] = 1 dm<sup>3</sup>.)
*100 [[millimetre|millimetre]]s
*3.9 [[inch]]es
*a side of a [[square (geometry)|square]] of area [[orders of magnitude (area)|0.01&nbsp;m<sup>2</sup>]]
*the edge of a [[cube (geometry)|cube]] with a volume of [[orders of magnitude (one cubic millimetre to one cubic metre)|{{val|1|e=-3}} m<sup>3</sup>]] (1 L)

===Wavelengths===
*10&nbsp;cm = 1.0 dm – wavelength of the highest [[ultra high frequency|UHF]] radio frequency, [[picosecond|3 GHz]]
*12&nbsp;cm = 1.2 dm – wavelength of the [[ISM band|2.45 GHz ISM radio band]]
*21&nbsp;cm = 2.1 dm – wavelength of the [[21 cm line|1.4 GHz hydrogen emission line]], a [[hyperfine structure|hyperfine]] transition of the hydrogen atom
*100&nbsp;cm = 10 dm – wavelength of the lowest UHF radio frequency, [[nanosecond|300 MHz]]

===Human-defined scales and structures===
*10.16&nbsp;cm = 1.016 dm – 1 [[hand (unit)|hand]] used in measuring height of horses (4&nbsp;inches)
*12&nbsp;cm = 1.2 dm – diametre of a compact disc (CD) (= 120&nbsp;mm)
*15&nbsp;cm = 1.5 dm – length of a [[Bic Cristal|Bic pen]] with cap on
*22&nbsp;cm = 2.2 dm – diametre of a typical association football (soccer ball)
*30&nbsp;cm = 3 dm – typical school-use ruler length (= 300&nbsp;mm)
*30.48&nbsp;cm = 3.048 dm – 1 [[foot (length)|foot]] (measure)
*60&nbsp;cm = 6 dm – standard depth (front to back) of a domestic kitchen worktop in Europe (= 600&nbsp;mm)
*90&nbsp;cm = 9 dm – average length of a rapier, a fencing sword<ref name="2-Clicks Swords"/>
*91.44&nbsp;cm = 9.144 dm – one [[yard]] (measure)

===Nature===
*10&nbsp;cm = 1 dm – diametre of the human [[cervix]] upon entering the second stage of labour
*11&nbsp;cm = 1.1 dm – length of an average potato in the U.S.
*13&nbsp;cm = 1.3 dm – body length of a [[Goliath birdeater]]
*15&nbsp;cm = 1.5 dm – approximate size of largest beetle species
*19&nbsp;cm = 1.9 dm – length of a banana
*26.3&nbsp;cm = 2.6 dm – length of average male human foot
*29.98&nbsp;cm = 2.998 dm – distance light in vacuum travels in one [[nanosecond]]
*30&nbsp;cm = 3.0 dm – maximum leg length of a Goliath birdeater
*31&nbsp;cm = 3.1 dm – wingspan of largest butterfly species [[Queen Alexandra's birdwing|''Ornithoptera alexandrae'']]
*32&nbsp;cm – length of the [[Goliath frog]], the world's largest frog
*46&nbsp;cm = 4.6 dm – length of an average domestic cat
*50 to 65&nbsp;cm = 5–6.5 dm – a coati's tail
*66&nbsp;cm = 6.6 dm – length of the longest pine cones (produced by the sugar pine<ref>{{cite web|url=http://www.na.fs.fed.us/Spfo/pubs/silvics_manual/Volume_1/pinus/lambertiana.htm|title=Pinus lambertiana|first1=Bohun B. Jr.|last1=Kinloch|first2=William H.|last2=Scheuner|name-list-style=amp|archive-url=https://web.archive.org/web/20110608015717/http://www.na.fs.fed.us/Spfo/pubs/silvics_manual/Volume_1/pinus/lambertiana.htm|archive-date=8 June 2011 |url-status=live|access-date=1 May 2017}}</ref>)

===Astronomical===
*84&nbsp;cm = 8.4 dm – approximate diametre of 2008 TS26, a meteoroid

==1 metre==
{{Redirect|1m||1M (disambiguation){{!}}1M}}

[[File:Da Vinci Vitruve Luc Viatour.jpg|thumb|Leonardo da Vinci drew the ''[[Vitruvian Man]]'' within a square of side {{cvt|1.83| m}} and a circle about {{cvt|1.2| m}} in radius.]]
To help compare different [[orders of magnitude]], this section lists lengths between one [[metre|metre]] and ten metres.
Light, in vacuum, travels 1 metre in {{frac|1|299,792,458}}, or {{#expr:1/299792458}} of a second.

===Conversions===
1 [[metre|metre]] is:
*10 [[decimetre|decimetre]]s
*100 [[centimetre|centimetre]]s
*1,000 [[millimetre|millimetre]]s
*39.37 [[inch]]es
*3.28 [[foot (length)|feet]]
*1.1 [[yard]]s
*side of [[square (geometry)|square]] with area [[1 E0 m²|1 m<sup>2</sup>]]
*edge of [[cube (geometry)|cube]] with surface area [[1 E0 m²|6 m<sup>2</sup>]] and volume [[1 E0 m³|1 m<sup>3</sup>]]
*radius of [[circle]] with area [[1 E0 m²|π m<sup>2</sup>]]
*radius of [[sphere]] with surface area [[1 E+1 m²|4π m<sup>2</sup>]] and volume [[1 E0 m³|4/3π m<sup>3</sup>]]

===Human-defined scales and structures===
*1 m – approximate height of the top part of a doorknob on a door
*1 m – diametre of a very large [[beach ball]]
*1.29 m – length of the [[Cross Island Chapel]], the smallest church in the world
*1.4 m – length of a [[Peel P50]], the world's smallest car
*1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4&nbsp;ft 8{{frac|1|2}} in
*2.5 m – distance from the floor to the ceiling in an average residential house<ref>{{cite web|url=http://htwins.net/scale/|title=HTwins.net – The Scale of the Universe|website=htwins.net|access-date=20 May 2017|archive-url=https://web.archive.org/web/20101129182745/http://htwins.net/scale/|archive-date=29 November 2010|url-status=dead}}</ref>
*2.7 m – length of the [[Starr Bumble Bee II]], the smallest plane
*2.77–3.44 m – wavelength of the broadcast radio FM band 87–108&nbsp;MHz
*3.05 m – the length of an old [[Mini]]
*8 m – length of the [[Tsar Bomba]], the largest bomb ever detonated
*8.38 m – the length of a London Bus ([[AEC Routemaster]])

===Sports===
*2.44 m – height of an association football goal<ref name=fifa>{{citation|title=Laws of the Game|url=http://resources.fifa.com/mm/document/footballdevelopment/refereeing/02/90/11/67/lawsofthegame2017-2018-en_neutral.pdf|publisher=FIFA|date=1 June 2017|access-date=21 March 2018|archive-date=13 November 2017|archive-url=https://web.archive.org/web/20171113060213/http://resources.fifa.com/mm/document/footballdevelopment/refereeing/02/90/11/67/lawsofthegame2017-2018-en_neutral.pdf|url-status=dead}}</ref>
*2.45 m – highest high jump by a human (Javier Sotomayor)<ref>{{citation|url=http://www.iaaf.org/statistics/toplists/inout=O/ageGroup=N/season=0/gender=M/discipline=HJ/legal=A/index.html|title=IAAF International Association of Athletics Federations – IAAF.org&nbsp;-&nbsp;Statistics&nbsp;-&nbsp;Top Lists|access-date=9 April 2010|archive-url=https://web.archive.org/web/20080116121100/http://www.iaaf.org/statistics/toplists/inout%3DO/ageGroup%3DN/season%3D0/gender%3DM/discipline%3DHJ/legal%3DA/index.html|archive-date=16 January 2008|url-status=dead}}</ref>
*3.05 m – (10 feet) height of the basket in basketball
*8.95 m – longest long jump by a human (Mike Powell)<ref>{{citation|title=IAAF International Association of Athletics Federations – IAAF.org&nbsp;-&nbsp;Past Results|access-date=9 April 2010|url=http://www2.iaaf.org/results/past/WCH91/data/M/LJ/Rf.html|archive-url=https://web.archive.org/web/20110604191419/http://www2.iaaf.org/results/past/WCH91/data/M/LJ/Rf.html|archive-date=4 June 2011|url-status=dead}}</ref>

===Nature===
*1 m – length of ''[[Rafflesia arnoldii]]'', the largest flower in the world
*1 m – height of ''[[Homo floresiensis]]'' (the "Hobbit")
<!-- * 1.1 m – length of the average erect elephant penis [commented out since no source provided, not mentioned in elephant article.] -->
*1.15 m – a [[pizote]] (mammal)
*1.5 m – height of an [[okapi]]
*1.63 m – (5&nbsp;feet 4&nbsp;inches, or 64&nbsp;inches) – height of average U.S. female human {{as of|2002|lc=on}} (source: U.S. Centers for Disease Control and Prevention (CDC))
*1.75 m – (5 feet 8 inches) – height of average U.S. male human {{As of|2002|lc=on}} (source: U.S. CDC as per female above)
*2.4 m – wingspan of a [[mute swan]]
*2.5 m – height of a [[sunflower]]
*2.7 m – length of a [[leatherback sea turtle]], the largest living turtle
*2.72 m – (8 feet 11 inches) – tallest-known human (Robert Wadlow)<ref name="Guinness"/>
*3 m – length of a [[giant Gippsland earthworm]]
*3 m – length of an [[Komodo dragon]], the largest living lizard
*3.63 m – the record wingspan for living birds (a [[wandering albatross]])
*3.7 m – leg span of a [[Japanese spider crab]]
*3.7 m – length of a [[southern elephant seal]], the largest living pinniped
*5 m – length of an [[elephant]]
*5.2 m – height of a [[giraffe]]<ref name="Dagg1971">{{citation|author=Dagg, A. I.|author-link=Anne Innis Dagg|year=1971|title=Mammalian Species 5|pages=1–8|edition=Giraffa camelopardalis}}</ref>
*5.5 m – height of a ''[[Baluchitherium]]'', the largest land mammal ever lived
*6.5 m – wingspan of ''[[Argentavis]]'', the largest flying bird known 
*6.7 m – length of a ''[[Microchaetus rappi]]''
*7.4 m – wingspan of ''[[Pelagornis]],'' the bird with longest wingspan ever.<ref>{{Cite news |date=7 July 2014 |title=Fossil of 'largest flying bird' identified |language=en-GB |work=BBC News |url=https://www.bbc.com/news/science-environment-28164063 |access-date=19 July 2022}}</ref>
*7.5 m – approximate length of the human gastrointestinal tract

===Astronomical===
*3–6 m – approximate diametre of {{mpl|2003 SQ|222}}, a meteoroid
*4.1 m – diametre of [[2008 TC3]], a small asteroid that flew into the Earth's atmosphere on 7 October 2008<ref name="discovermagazine">{{cite web|url=http://blogs.discovermagazine.com/badastronomy/2008/10/06/incoming-2/|title=Incoming!!!|last=Plait|first=P.|date=6 October 2008|publisher=[[Bad Astronomy]]|access-date=8 October 2008|archive-url=https://web.archive.org/web/20081007190747/http://blogs.discovermagazine.com/badastronomy/2008/10/06/incoming-2/|archive-date=7 October 2008|url-status=live}}</ref>

==1 decametre==
[[File:Image-Blue Whale and Hector Dolphine Colored.jpg|thumb|A [[blue whale]] has been measured as {{cvt|33| m}} long; this drawing compares its length to that of a human diver and a dolphin.]]

The ''{{vanchor|[[decametre]]}}'' ([[SI]] symbol: ''{{vanchor|dam}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10&nbsp;[[metre|metre]]s (10<sup>1</sup>&nbsp;m). 
To help compare different [[orders of magnitude]], this section lists lengths between 10 and 100 metres.<!-- please avoid using abbreviations when the full name is clearer to the reader; please use commonly used terms and not rarely used terms -->

===Conversions===
10 metres (very rarely termed a [[decametre|decametre]] which is abbreviated as dam) is equal to:
*10 metres
*100 [[decimetre|decimetre]]s
*1,000 [[centimetre|centimetre]]s
*10,000 [[millimetre|millimetre]]s
* 10,000,000 [[micrometre|micrometre]]s (or rarely 10,000,000 microns)
*32.8 [[foot (length)|feet]]
*11 [[yards]]
*side of a [[square (geometry)|square]] with area [[1 E+2 m²|100 m²]]

===Human-defined scales and structures===
*10 metres – wavelength of the highest shortwave radio frequency, [[1 E7 Hz|30]] M[[hertz|Hz]]
*10.2 metres – length of the [[Panzer VIII Maus]], the world's largest tank
*12 metres – height of the [[Newby-McMahon Building]], the world's littlest skyscraper
*23 metres – height of [[Luxor Obelisk]], located in the Place de la Concorde, Paris, France
*25 metres – wavelength of the broadcast radio shortwave band at [[1 E7 Hz|12]] MHz
*29 metres – height of the [[Savudrija Lighthouse]]
*30 metres – height of [[Christ the Redeemer (statue)|Christ the Redeemer]] 
*31 metres – wavelength of the broadcast radio shortwave band at 9.7&nbsp;MHz
*32 metres – length of one [[Minute and second of arc|arcsecond]] of [[latitude]] on the surface of the [[Earth]]
*33.3 metres – height of the [[De Noord]], the tallest windmill in the world
*34 metres – height of the [[Split Point Lighthouse]] in Aireys Inlet, Victoria, Australia
*40 metres – wingspan of the [[Mil Mi-26]], the largest helicopter
*40 metres – average depth beneath the seabed of the [[Channel tunnel]]
*49 metres – wavelength of the broadcast radio shortwave band at 6.1&nbsp;MHz
*50 metres – length of a [[road train]]
*50 metres – height of the [[Arc de Triomphe]]
*55 metres – height of the [[Leaning Tower of Pisa]]
*62 metres – wingspan of [[Concorde]]
*62.5 metres – height of [[Pyramid of Djoser]]
*64 metres – wingspan of a [[Boeing 747-400]]
*69 metres – wingspan of an [[Antonov An-124 Ruslan]]
*70 metres – length of the [[Bayeux Tapestry]]
*70 metres – width of a typical [[association football field]]
*73 metres – wingspan of a [[Airbus A380]]
*73 metres – height of the [[Taj Mahal]]
*77 metres – wingspan of a [[Boeing 747-8]]
*88.4 metres – wingspan of an [[Antonov An-225 Mriya]] transport aircraft
*93 metres – height of the [[Statue of Liberty]] (''Liberty Enlightening the World'')
*96 metres – height of [[Big Ben]]
*100 metres – wavelength of the lowest shortwave radio frequency, [[1 E6 Hz|3]] MHz

===Sports===
*11 metres – approximate width of a doubles tennis court
*15 metres – width of a standard FIBA basketball court
*15.24 metres – width of an NBA basketball court (50&nbsp;feet)
*18.44 metres – distance between the front of the pitcher's rubber and the rear point of home plate on a baseball field (60 feet, 6&nbsp;inches)<ref>{{cite web|url=http://mlb.mlb.com/mlb/downloads/y2010/official_rules/2010_OfficialBaseballRules.pdf|title=Rule 1.04 The Playing Field|website=Official Baseball Rules|publisher=[[Major League Baseball]]|pages=1–5|date=25 January 2010|access-date=1 April 2011|archive-url=https://web.archive.org/web/20110427083014/http://mlb.mlb.com/mlb/downloads/y2010/official_rules/2010_OfficialBaseballRules.pdf|archive-date=27 April 2011 |url-status=live}} See especially Diagram No. 1, page 3.</ref>
*20 metres – length of cricket pitch (22 yards)<ref>{{cite web|url=http://www.lords.org/laws-and-spirit/laws-of-cricket/laws/law-7-the-pitch,33,AR.html|title=Law 7 (The pitch)|website=Laws of Cricket|publisher=[[Marylebone Cricket Club]]|date=October 2010|access-date=1 April 2011|archive-url=https://web.archive.org/web/20110514141304/http://www.lords.org/laws-and-spirit/laws-of-cricket/laws/law-7-the-pitch%2C33%2CAR.html|archive-date=14 May 2011|url-status=dead}}</ref>
*27.43 metres – distance between bases on a baseball field (90&nbsp;feet)
*28 metres – length of a standard FIBA basketball court
*28.65 metres – length of an NBA basketball court (94&nbsp;feet)
*49 metres – width of an American football field (53{{frac|1|3}} yards)
*59.436 metres – width of a Canadian football field (65 yards)
*70 metres – typical width of an association football field
*91 metres – length of an American football field (100 yards, measured between the goal lines)

===Nature===
*10 metres – average length of human digestive tract{{citation needed|date=November 2010}}
*12 metres – height of a [[saguaro cactus]]
*12 metres – length of a [[whale shark]], largest living fish
*12 metres – wingspan of a ''[[Quetzalcoatlus]]'', a pterosaur
*12.8 metres – length of a ''[[Titanoboa]]'', the largest snake to have ever lived
*13 metres – length of a [[giant squid]] and [[colossal squid]], the largest living invertebrates
*15 metres – approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt
*16 metres – length of a [[sperm whale]], the largest toothed whale
*18 metres – height of a ''[[Sauroposeidon]]'', the tallest-known dinosaur
*20 metres – length of a ''[[Leedsichthys]]'', the largest-known fish to have lived
*21 metres – height of [[High Force]] waterfall in England
*30.5 metres – length of the [[lion's mane jellyfish]], the largest jellyfish in the world
*33 metres – length of a [[blue whale]],<ref>{{cite web|url=http://nationalzoo.si.edu/Animals/AnimalRecords/|title=Animal Records|publisher=Smithsonian National Zoological Park|access-date=29 May 2007|archive-url=https://web.archive.org/web/20090328113538/http://nationalzoo.si.edu/Animals/AnimalRecords/|archive-date=28 March 2009|url-status=live}}</ref> the largest animal on earth, living or extinct, in terms of mass
*39 metres – length of a ''[[Supersaurus]]'', the longest-known dinosaur and longest vertebrate<ref>{{Cite web|last=Curtice|first=Brian|date=2021|title=New Dry Mesa Dinosaur Quarry Supersaurus vivianae (Jensen 1985) axial elements provide additional insight into its phylogenetic relationships and size, suggesting an animal that exceeded 39 metres in length|url=https://vertpaleo.org/wp-content/uploads/2021/10/SVP_2021_VirtualBook_final.pdf#page91}}</ref>
*52 metres – height of [[Niagara Falls]]<ref name="Niagara Parks Commission"/>
*55 metres – length of a [[bootlace worm]], the longest-known animal<ref>{{cite web|url=https://www.guinnessworldrecords.com/world-records/longest-animal/|title=Longest Animal|publisher=Guinness World Records|access-date=15 June 2019}}</ref>
*66 metres – highest possible sea level rise due to a complete melting of all ice on Earth
*83 metres – height of a [[western hemlock]]
*84 metres – height of [[General Sherman Tree|General Sherman]], the largest tree in the world

===Astronomical===
*30 metres – diametre of {{mpl|1998 KY|26}}, a rapidly spinning meteoroid
*30.8568 metres – 1 femtoparsec
*32 metres – approximate diametre of [[2008 HJ]], a small meteoroid

==1 hectometre==
[[File:Cheops pyramid 01.jpg|thumb|The Great Pyramid of Giza is {{cvt|138.8| m}} high.]]
[[File:M27 DLS.JPG|thumb|upright|British [[Driver location signs|driver location sign]] and location marker post on the [[M27 motorway|M27]] in [[Hampshire]]. The location marker posts are installed at 100-metre intervals.<ref name=faq>{{cite web
|url=http://www.highways.gov.uk/business/16049.htm
|title=Driver Location Signs – Frequently Asked Questions
|publisher=Highways Agency
|access-date=10 February 2010
|url-status=dead
|archive-url=http://webarchive.nationalarchives.gov.uk/20120810121037/http://www.highways.gov.uk/business/16049.htm
|archive-date=10 August 2012

}}</ref>]]

The ''{{vanchor|[[hectometre]]}}'' ([[SI]] symbol: ''{{vanchor|hm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 100&nbsp;[[metre|metre]]s (10<sup>2</sup>&nbsp;m). 
To compare different [[orders of magnitude]] this section lists lengths between 100 metres and 1,000 metres (1 [[kilometre|kilometre]]). <!-- please avoid using abbreviations when the full name is clearer to the reader; please use commonly used terms and not rarely used terms -->

===Conversions===
100 metres (sometimes termed a hectometre) is equal to:

*328 [[foot (length)|feet]]
*one side of a [[1 E+4 m²|1 hectare]] square
*a fifth of a modern [[li (Chinese unit)|li]], a Chinese unit of measurement
*the approximate distance travelled by light in 300 [[nanosecond]]s

===Human-defined scales and structures===
*100 metres – wavelength of the highest medium wave radio frequency, [[1 E6 Hz|3 MHz]]
*100 metres – spacing of location marker posts on British motorways
*110 metres – height of the [[Saturn V]]
*122 metres – height of the [[SpaceX Starship|Starship]], the tallest rocket currently under development by [[SpaceX]]
*138.8 metres – height of the [[Great Pyramid of Giza]] (Pyramid of Cheops)
*139 metres – height of the world's tallest roller coaster, [[Kingda Ka]]<ref>{{cite web|url=https://rcdb.com/2832.htm|title=Kingda Ka (Six Flags Great Adventure)|access-date=18 April 2009|archive-url=https://web.archive.org/web/20090326124600/http://www.rcdb.com/id2832.htm|archive-date=26 March 2009|url-status=live}}</ref>
*157 metres – height of the [[Cologne Cathedral]]
*162 metres – height of the [[Ulm Minster]], the tallest church building in the world
*165 metres – height of the [[Dushanbe Flagpole]], the tallest flagpole from May 2011 to September 2014
*169 metres – height of the [[Washington Monument]]
*171 metres – height of the	[[Jeddah Flagpole]], the tallest flagpole from September 2014 to December 2021
*182 metres – height of the ''[[Statue of Unity]]'', the world's tallest statue
*187 metres – shortest wavelength of the broadcast radio AM band, [[1 E6 Hz|1600 kHz]]
*192 metres – height of the [[Gateway Arch]]
*202 metres – height of the [[Cairo Flagpole]], the tallest flagpole as of December 2021
*202 metres – length of the [[Széchenyi Chain Bridge]] connecting Buda and Pest
*220 metres – height of the [[Hoover Dam]]
*245 metres – length of the [[LZ 129 Hindenburg]]
*270 metres – length of the ''[[Titanic]]''
*318 metres – height of The [[New York Times Building]]
*318.9 metres – height of the [[Chrysler Building]]
*328 metres – height of Auckland's [[Sky Tower (Auckland)|Sky Tower]], the tallest free-standing structure in the Southern Hemisphere (1996–2022)
*330 metres – height of the [[Eiffel Tower]] (including antenna)<ref>{{Cite news|url=https://www.reuters.com/world/europe/eiffel-tower-grows-six-metres-after-new-antenna-attached-2022-03-15/|title=Eiffel Tower grows six metres after new antenna attached|website=Reuters |date=15 March 2022 }}</ref>
*336 metres – height of the world's tallest bridge as of October 2023, the [[Millau Viaduct]]
*364.75 metres – length of the [[Icon of the Seas]]
*390 metres – height of the [[Empire State Building]]
*400–800 metres – approximate heights of the world's tallest skyscrapers from 1931 to 2010
*458 metres – length of the [[Knock Nevis]], the world's largest supertanker
*553.33 metres – height of the [[CN Tower]],<ref>{{cite news|url=https://www.tripsavvy.com/how-tall-is-the-cn-tower-3251128|title=How Tall is the CN Tower?|work=TripSavvy|access-date=20 May 2017|last=Campbell|first=Marilyn|date=17 February 2018}}</ref> the tallest structure in North America
*555 metres – longest wavelength of the broadcast radio AM band, [[1 E5 Hz|540 kHz]]
*630 metres – height of the [[KVLY-TV mast]], one of the tallest structures in the world
*646 metres – height of the [[Warsaw radio mast]], the world's tallest structure until its collapse in 1991
*679 metres – height of [[Merdeka 118]], the second tallest structure in [[Kuala Lumpur]], [[Malaysia]]
*828 metres – height of [[Burj Khalifa]], world's tallest structure since 17 January 2009<ref>{{cite news|url=http://www.business24-7.ae/articles/2009/1/pages/01182009_63dc3a90c9a848219058be301f3f7ded.aspx|title=Burj Dubai all set for 09/09/09 soft opening|work=Emirates Business 24-7|access-date=17 January 2009|archive-url=https://web.archive.org/web/20090119161147/http://business24-7.ae/Articles/2009/1/Pages/01182009_63dc3a90c9a848219058be301f3f7ded.aspx|archive-date=19 January 2009 |url-status=live}}</ref>
*1,000 metres – wavelength of the lowest mediumwave radio frequency, [[1 E5 Hz|300 kHz]]

===Sports===
*100 metres – the distance a very fast human can run in about 10 seconds
*100.584 metres – length of a Canadian football field between the goal lines (110 [[yard]]s)
*91.5 metres – 137 metres – length of a soccer field<ref name=fifa/>
*105 metres – length of football pitch (UEFA stadium categories 3 and 4)
*105 metres – length of a typical football field
*109.73 metres – total length of an American football field (120 yards, including the end zones)
*110–150 metres – the width of an Australian football field
*135–185 metres – the length of an Australian football field
*137.16 metres – total length of a Canadian football field, including the end zones (150 yards)

===Nature===
*115.5 metres – height of the world's tallest tree in 2007, the [[Hyperion (tree)|Hyperion]] sequoia<ref>{{cite web|url=https://www.monumentaltrees.com/en/trees/coastredwood/coastredwood/|title=Tallest tree in the world: coast redwood|website=Monumental Trees, an inventory of big and old trees worldwide}}</ref>
*310 metres – maximum depth of [[Lake Geneva]]
*340 metres – distance sound travels in air at sea level in one second; see [[Speed of sound]]
*947 metres – height of the [[Tugela Falls]], the highest waterfall in Africa
*979 metres – height of the [[Angel Falls]], the world's highest free-falling waterfall (Venezuela)

===Astronomical===
*270 metres – length of [[99942 Apophis]]
*535 metres – length of [[25143 Itokawa]],<ref>{{cite journal|vauthors=Fujiwara A, Kawaguchi J, Yeomans DK, Abe M, Mukai T, Okada T, Saito J, Yano H, Yoshikawa M, Scheeres DJ, Barnougin-Jha O, Cheng AF, Demura H, Gaskell RW, Hirata N, Ikeda H, Kominato T, Miyamoto H, Nakamura AM, Nakamura R, Sasaki S, Uesugi K|title=The rubble-pile asteroid Itokawa as observed by Hayabusa|journal=Science|volume=312|issue=5778|pages=1330–4|date=June 2006|pmid=16741107|doi=10.1126/science.1125841|bibcode=2006Sci...312.1330F|s2cid=206508294}}</ref> a small asteroid visited by a spacecraft

==1 kilometre==
[[File:Fuji_Kawaguchi_357.JPG|thumb|[[Mount Fuji]] is {{Convert|3.776|km|mi}} high.]]

The ''{{vanchor|[[kilometre]]}}'' ([[SI]] symbol: ''{{vanchor|km}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{gaps|1|000}}&nbsp;[[metre|metre]]s (10<sup>3</sup>&nbsp;m). 
To help compare different [[orders of magnitude]], this section lists [[length]]s between 1&nbsp;kilometre and 10&nbsp;[[kilometre|kilometre]]s (10<sup>3</sup> and 10<sup>4</sup> [[metre|metre]]s).

===Conversions===
1 [[kilometre|kilometre]] (unit symbol km) is equal to:

*1,000 [[metre|metre]]s
*0.621371 [[mile]]s
*1,093.61 [[yard]]s
*3,280.84 [[foot (length)|feet]]
*39,370.1 [[inch]]es
*100,000 [[centimetre|centimetre]]s
*1,000,000 [[millimetre|millimetre]]s
*Side of a [[square (geometry)|square]] of area [[1 E+6 m²|1]] [[Km²|km<sup>2</sup>]]
*Radius of a [[circle]] of area [[Pi|&pi;]] km<sup>2</sup>

===Human-defined scales and structures===
*1&nbsp;km – wavelength of the highest [[long wave]] radio frequency, [[1 E5 Hz|300]] [[kHz]]<ref>{{cite web|url=https://en.oxforddictionaries.com/definition/long_wave|archive-url=https://web.archive.org/web/20190301140144/https://en.oxforddictionaries.com/definition/long_wave|url-status=dead|archive-date=1 March 2019|title=long wave|publisher=Oxford Dictionaries|quote=wavelength above one kilometre (and a frequency below 300 kHz)|access-date=12 March 2011}}</ref>
*1.008 km – proposed height of the [[Jeddah Tower]], a [[megatall skyscraper]] under construction in [[Saudi Arabia]]
*1.280&nbsp;km – span of the [[Golden Gate Bridge]] (distance between towers)<ref>{{cite web|title=Bridge Design and Construction Statistics |website=Golden Gate Bridge |url=http://goldengatebridge.org/research/factsGGBDesign.php#length|access-date=10 June 2012 |url-status=dead |archive-url= https://web.archive.org/web/20120614021631/http://goldengatebridge.org/research/factsGGBDesign.php#length |archive-date= Jun 14, 2012 }}</ref>
*1.609&nbsp;km – 1 statute mile
*1.852&nbsp;km – 1 [[nautical mile]], equal to 1 [[arcminute]] of [[latitude]] at the surface of the Earth<ref>{{cite Merriam-Webster|nautical mile|access-date=12 March 2011}}</ref>
*1.991&nbsp;km – span of the [[Akashi Kaikyō Bridge]]<ref>{{citation|title=Akashi Kaikyo Bridge @ Everything2.com|url=https://everything2.com/title/Akashi%2520Kaikyo%2520Bridge|publisher=[[Everything2]]|date=9 September 2002|access-date=19 April 2009}}</ref>
*2.309&nbsp;km – axial length of the [[Three Gorges Dam]], the largest [[dam]] in the world located in [[China]]<ref name="Three Gorges Dam"/>
*3.991&nbsp;km – length of the [[Akashi Kaikyō Bridge]], longest [[suspension bridge]] in the world {{as of|2008|December|lc=on}}<ref>{{citation|title=Supporting the Longest Suspension Bridge in the World|url=http://regex.info/blog/2008-12-09/1021|first=Jeffrey|last=Friedl|date=9 December 2008|access-date=19 April 2009|archive-url=https://web.archive.org/web/20090303135910/http://regex.info/blog/2008-12-09/1021|archive-date=3 March 2009|url-status=live}}</ref>
*4&nbsp;km – width of [[Central Park]]
*5.072&nbsp;km – elevation of [[Tanggula Mountain Pass]], below highest peak in the [[Tanggula Mountains]], highest [[railway]] pass in the world {{as of|2005|08|lc=on}}<ref>{{citation|title=New height of world's railway born in Tibet|url=http://news.xinhuanet.com/english/2005-08/24/content_3397297.htm|publisher=[[Xinhua News Agency]]|date=24 August 2005|access-date=19 April 2009|archive-url=https://web.archive.org/web/20090603005131/http://news.xinhuanet.com/english/2005-08/24/content_3397297.htm|archive-date=3 June 2009|url-status=dead}}</ref>
*5.8&nbsp;km – elevation of Cerro Aucanquilcha, highest road in the world, located in [[Chile]]<ref>{{cite web|url=http://andes.org.uk/peak-info-6000/aucanquilcha-info.asp|title=Aucanquilcha 6176m|work=Andes|access-date=3 July 2024}}</ref>
*[[List of longest runways|98 airports]] have paved runways from 4&nbsp;km to 5.5&nbsp;km in length.
*8&nbsp;km – length of [[Palm Jebel Ali]], an [[artificial island]] built off the coast of [[Dubai]]
*9.8&nbsp;km – length of [[The World (archipelago)|The World]], an artificial archipelago that is also built off the coast of [[Dubai]], whose islands resemble a [[world map]]

===Nature===
*1.5&nbsp;km – distance sound travels in water in one second

===Geographical===
{{More citations needed section|date=March 2011|reason=each needs a cite, to aid verification}}
{{See also|List of highest mountains on Earth}}
*1.637&nbsp;km – deepest dive of [[Lake Baikal]] in [[Russia]], the world's largest [[freshwater]] [[lake]]<ref>{{cite news|url=http://news.bbc.co.uk/2/hi/europe/7530230.stm|title=Russians in landmark Baikal dive|date=29 July 2008|work=BBC News|quote=current record of 1,637m was set in Lake Baikal in the 1990s|access-date=12 March 2011}}</ref>
*2.228&nbsp;km – height of [[Mount Kosciuszko]], highest point on mainland [[Geography of Australia|Australia]]<ref>{{cite web|title=Kosciuszko National Park lookouts and scenery|url=https://www.nationalparks.nsw.gov.au/visit-a-park/parks/kosciuszko-national-park#WallacesCreeklookout|publisher=Office of Environment & Heritage: NSW National Parks & Wildlife Service}}</ref>
*Most of [[Manhattan]] is from 3 to 4&nbsp;km wide.
*3.776&nbsp;km – height of [[Mount Fuji]], highest peak in [[Japan]]
*4.478&nbsp;km – height of [[Matterhorn]]
*4.509&nbsp;km – height of [[Mount Wilhelm]], highest peak in [[Papua New Guinea]]
*4.810&nbsp;km – height of [[Mont Blanc]], highest peak in the [[Alps]]
*4.884&nbsp;km – height of [[Carstensz Pyramid]], highest peak in [[Oceania]]<ref>{{cite web|title=Carstensz Pyramid details|url=http://carstenszpyramid.org/|publisher=Carstensz Pyramid Site|url-status=dead|archive-url=https://web.archive.org/web/20141216212851/http://carstenszpyramid.org/|archive-date=16 December 2014}}</ref>
*4.892&nbsp;km – height of [[Mount Vinson]], highest peak in [[Antarctica]]
*5.610&nbsp;km – height of [[Mount Damavand]], highest peak in [[Iran]]
*5.642&nbsp;km – height of [[Mount Elbrus]], highest peak in [[Europe]]
*5.895&nbsp;km – height of [[Mount Kilimanjaro]], highest peak in [[Africa]]
*6.081&nbsp;km – height of [[Mount Logan]], highest peak in [[Canada]]
*6.190&nbsp;km – height of [[Denali]], highest peak in [[North America]]
*6.959&nbsp;km – height of [[Aconcagua]], highest peak in [[South America]]
*7.5&nbsp;km – depth of [[Cayman Trench]], deepest point in the [[Caribbean Sea]]
*8.611&nbsp;km – height of [[K2]], second highest peak on [[Earth]]
*8.848&nbsp;km – height of [[Mount Everest]], highest peak on [[Earth]], on the border between [[Nepal]] and [[China]]

===Astronomical===
*1&nbsp;km – diametre of [[1620 Geographos]]
*1&nbsp;km – very approximate size of the smallest-known [[moons of Jupiter]]
*1.4&nbsp;km – diametre of [[Dactyl (asteroid)|Dactyl]], the first confirmed [[asteroid moon]]
*4.8&nbsp;km – diametre of [[5535 Annefrank]], an inner belt asteroid
*5&nbsp;km – diametre of [[3753 Cruithne]]
*5&nbsp;km – length of [[PSR B1257+12]]
*8&nbsp;km – diametre of [[Themisto (moon)|Themisto]], one of [[Jupiter]]'s moons
*8&nbsp;km – diametre of the [[Vela Pulsar]]
*8.6&nbsp;km – diametre of [[Callirrhoe (moon)|Callirrhoe]], also known as Jupiter XVII
*9.737&nbsp;km – length of [[PSR B1919+21]]

=={{Anchor|Myriametre}}10 kilometres (1 myriametre)==
[[File:Strait of Gibraltar 5.53940W 35.97279N.jpg|thumb|The [[Strait of Gibraltar]] is {{cvt|13| km}} wide.]]

To help compare different [[orders of magnitude]], this section lists [[length]]s between 10 and 100 [[kilometre|kilometre]]s (10<sup>4</sup> to 10<sup>5</sup> [[metre|metre]]s). The ''myriametre''<ref name="Appell_2009">{{cite web|url=http://home.fonline.de/fo0126/geschichte/groessen/mas10.htm|title=Königreich Frankreich|author-last=Appell|author-first=Wolfgang|date=16 September 2009|website=Amtliche Maßeinheiten in Europa 1842 [Official units of measure in Europe 1842]|language=de|trans-title=Kingdom of France|orig-year=2002|url-status=dead|archive-url=https://web.archive.org/web/20111005102232/http://home.fonline.de/fo0126/geschichte/groessen/mas10.htm|archive-date=5 October 2011}} (Website based on ''Alte Meß- und Währungssysteme aus dem deutschen Sprachgebiet'', {{ISBN|3-7686-1036-5}}<!-- see http://d-nb.info/952290928 -->)</ref> (sometimes also spelled ''myriometre''; 10,000 metres) is a deprecated unit name; the decimal metric prefix [[myria-]]<ref name="fr">{{cite web|title=La Loi Du 18 Germinal An 3 – Décision de tracer le mètre, unité fondamentale, sur une règle de platine. Nomenclature des "mesures républicaines". Reprise de la triangulation|url=http://histoire.du.metre.free.fr/fr/Pages/Sommaire/06.htm|language=fr|publisher=histoire.du.metre.free.fr|access-date=12 October 2015}}</ref> (sometimes also written as [[myrio-]]<ref name="Brewster_1830">{{cite book|title=The Edinburgh Encyclopædia|author-first=David|author-last=Brewster|volume=12|date=1830|location=Edinburgh, UK|publisher=William Blackwood, John Waugh, John Murray, Baldwin & Cradock, J. M. Richardson|page=494|url=https://books.google.com/books?id=0bIkTUZAbxcC|access-date=9 October 2015}}</ref><ref name="Brewster_1832">{{cite book|title=The Edinburgh Encyclopaedia|author-first=David|author-last=Brewster|volume=12|edition=1st American|date=1832|publisher=Joseph and Edward Parker<!--|printer=William Brows -->|url=https://books.google.com/books?id=17RGAQAAIAAJ&pg=PA572|access-date=9 October 2015}}</ref><ref name="Dingler_1823">{{cite book|title=Polytechnisches Journal|author-first=Johann Gottfried|author-last=Dingler|volume=11|date=1823|publisher=J.W. Gotta'schen Buchhandlung|language=de|location=Stuttgart, Germany|url=https://books.google.com/books?id=wF3zAAAAMAAJ&pg=PA500|access-date=9 October 2015}}</ref>) is obsolete<ref name="Procès-Verbaux_1935">{{citation |title=Procès-Verbaux des Séances|author=Comité International des Poids et Mesures|author-link=Comité International des Poids et Mesures|publisher=Gauthier-Villars, imprimeur-libraire du [[Bureau des Longitudes]], de l'[[École Polytechnique]]|location=Paris, France|language=fr|edition=2|volume=17|date=1935|page=76}}</ref><ref name="Roberts_1975">{{cite book|title=Metric System of Weights and Measures – Guidelines for Use|author-first=Richard W.|author-last=Roberts|publisher=Director of the [[National Bureau of Standards]]|location=US|id=Federal Register FR Doc.75-15798 (18 June 1975)|date=1 June 1975|quote=Accordingly, the following units and terms listed in the table of metric units in section 2 of the act of 28 July 1866, that legalized the metric system of weights and measures in the United States, are no longer accepted for use in the United States: myriametre, [[stere]], [[millier (unit)|millier]] or [[tonneau (unit)|tonneau]], [[quintal]], [[myriagram]], kilo (for kilogram).}}</ref><ref name="Judson_1976">{{cite book|title=Weights and Measures Standards of the United States, a brief history|author-first=Lewis V.|author-last=Judson|others=Derived from a prior work by Louis A. Fisher (1905)|editor-first=Louis E.|editor-last=Barbrow|publisher=[[US Department of Commerce]], [[National Bureau of Standards]]|location=US|date=1 October 1976|orig-year=1963<!-- 1963-03 -->|id=NBS Special Publication 447; NIST SP 447; 003-003-01654-3|lccn=76-600055|page=33|chapter=Appendix 7|chapter-url=https://www.nist.gov/pml/wmd/pubs/upload/sp-447-2.pdf|access-date=12 October 2015|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304193400/http://www.nist.gov/pml/wmd/pubs/upload/sp-447-2.pdf|url-status=dead}}</ref> and was not included among the [[SI prefixes|prefixes]] when the [[International System of Units]] was introduced in 1960.

===Conversions===
10 kilometres is equal to:
[[File:Myriameterstein36RüdesheimRhein.JPG|thumb|[[Distance marker]] on the [[Rhine]]: 36 (XXXVI) myriametres from [[Basel]]. The stated distance is {{cvt|360| km}}; the comma is the [[decimal separator]] in [[Germany]].]]
*10,000 [[metre|metre]]s
*About 6.2 [[mile]]s
*1 ''mil (the [[Scandinavian mile]])'', now standardized as 10&nbsp;km:
**1 mil, the unit of measure commonly used in [[Norway]] and [[Sweden]]<ref name="Haugen">Haugen, Einar, ''Norwegian English Dictionary,'' 1965, Oslo: Universitetsforlaget and Madison: [[University of Wisconsin Press]], s.v. mil</ref> used to be 11,295&nbsp;m in Norway and 10,688&nbsp;m in Sweden.
*''[[Parasang|farsang]]'', unit of measure commonly used in [[Iran]] and [[Turkey]]<ref>{{cite web|url=https://sizes.com/units/farsakh.htm|title=What is a farsakh or farsang?|website=sizes.com}}</ref>

===Sports===
*42.195&nbsp;km – length of the [[marathon]]<ref>{{cite web|url=http://www.iaaf.org/mm/Document/imported/42192.pdf|title=IAAF Competition Rules 2008|page=195|publisher=[[International Association of Athletics Federations|IAAF]]|access-date=20 April 2009|archive-url=https://web.archive.org/web/20090325001003/http://www.iaaf.org/mm/Document/imported/42192.pdf|archive-date=25 March 2009|url-status=live}}</ref>

===Human-defined scales and structures===
*18&nbsp;km – cruising altitude of [[Concorde]]
*27&nbsp;km – circumference of the [[Large Hadron Collider]], {{as of|May 2010|lc=on}} the largest and highest energy [[particle accelerator]]
*34.668&nbsp;km – highest manned [[balloon]] flight (Malcolm D. Ross and Victor E. Prather on 4 May 1961)<ref>{{cite web|url=http://stratocat.com.ar/artics/stratolab-e.htm|title=Stratolab, an Evolutionary Stratospheric Balloon Project|first=Gregory|last=Kennedy}}</ref>
*38.422&nbsp;km – length of the Second [[Lake Pontchartrain Causeway]] in [[Louisiana]], U.S.
*39&nbsp;km – undersea portion of the [[Channel tunnel]]
*53.9&nbsp;km – length of the [[Seikan Tunnel]], {{as of|2009|10|lc=on}}, the longest rail tunnel in the world<ref>{{cite web|title=Turkey Building the World's Deepest Immersed Tube Tunnel|url=https://www.popularmechanics.com/technology/design/a1689/4217338/|first=Jeff|last=Wise|website=[[Popular Mechanics]]|date=1 October 2009|access-date=1 May 2017}}</ref>
*77&nbsp;km – rough total length of the [[Panama Canal]]<ref>{{Cite web | url=http://panamacanalfacts.com/facts-about-the-panama-canal/ | archive-url=https://web.archive.org/web/20160314232748/http://panamacanalfacts.com/facts-about-the-panama-canal/ | url-status=dead | archive-date=14 March 2016 | title=Facts and History about the Panama Canal}}</ref>

===Geographical===
*10&nbsp;km – height of [[Mauna Kea]] in [[Hawaii]], measured from its base on the ocean floor
*11&nbsp;km – deepest-known point of the ocean, [[Challenger Deep]] in the [[Mariana Trench]]
*11&nbsp;km – average height of the [[troposphere]]
*14&nbsp;km – width of the [[Strait of Gibraltar]]
*21&nbsp;km – length of [[Manhattan]]
*22&nbsp;km – narrowest width of the [[Cook Strait]] between New Zealand's main islands
*23&nbsp;km – depth of the [[1931 Dogger Bank earthquake|largest earthquake ever recorded in the United Kingdom]], in 1931 at the [[Dogger Bank]] of the [[North Sea]]
*34&nbsp;km – narrowest width of the [[English Channel]] at the [[Strait of Dover]]
*50&nbsp;km – approximate height of the [[stratosphere]]
*90&nbsp;km – width of the [[Bering Strait]]

===Astronomical===
*10&nbsp;km – diametre of the most massive [[neutron star]]s (3–5 [[solar mass]]es)
*13&nbsp;km – mean diametre of [[Deimos (moon)|Deimos]], the smaller moon of [[Mars]]
*20&nbsp;km – diametre of the least massive neutron stars (1.44 solar masses)
*20&nbsp;km – diametre of [[Leda (moon)|Leda]], one of [[Jupiter]]'s moons
*20&nbsp;km – diametre of [[Pan (moon)|Pan]], one of [[Saturn]]'s moons
*22&nbsp;km – diametre of [[Phobos (moon)|Phobos]], the larger moon of [[Mars]]
*27&nbsp;km – height of [[Olympus Mons]] above the [[Mars]] reference level,<ref>[http://quest.arc.nasa.gov/mars/ask/terrain-geo/highest_and_lowest_points_on_Mars.txt Highest and lowest points on Mars] {{webarchive|url=https://web.archive.org/web/20160131060040/http://quest.arc.nasa.gov/mars/ask/terrain-geo/highest_and_lowest_points_on_Mars.txt|date=31 January 2016}} NASA</ref><ref>{{cite web|url=http://quest.arc.nasa.gov/mars/ask/terrain-geo/Height_of_Martian_vs__Earth_mountains.txt|title=Height of Martian vs. Earth mountains|last=Plescia|first=Jeff|date=1 October 1997|website=Questions and Answers about Mars terrain and geology|access-date=20 April 2009|archive-url=https://web.archive.org/web/20081014140612/http://quest.arc.nasa.gov/mars/ask/terrain-geo/Height_of_Martian_vs__Earth_mountains.txt|archive-date=14 October 2008|url-status=dead}}</ref> the highest-known mountain of the [[Solar System]]
*30.8568&nbsp;km – 1 picoparsec
*43&nbsp;km – diametre difference of [[Earth]]'s [[equatorial bulge]]
*66&nbsp;km – diametre of [[Naiad (moon)|Naiad]], the innermost of [[Neptune]]'s moons

==100 kilometres==
[[File:Suez canal 30.55N 32.28E.jpg|thumb|upright|The [[Suez Canal]] is {{cvt|163| km}} long.]]
A length of ''100 kilometres'' (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects.
It is the altitude at which the [[Fédération Aéronautique Internationale|FAI]] defines [[spaceflight]] to begin.

To help compare [[orders of magnitude]], this section lists [[length]]s between 100 and 1,000 [[kilometre|kilometre]]s (10<sup>5</sup> and 10<sup>6</sup> [[metre|metre]]s).

===Conversions===
A distance of 100 kilometres is equal to about 62 miles (or {{convert|100|km|8|disp=out|abbr=in}}).

===Human-defined scales and structures===
<!-- Note: non-breaking space &nbsp; is not needed near the start of a line -->
*100&nbsp;km – the [[Karman line]]: the internationally recognized boundary of [[outer space]]
*105&nbsp;km – distance from [[Giridih]] to [[Bokaro Steel City|Bokaro]]
*109&nbsp;km – length of [[High Speed 1]] between London and the Channel Tunnel<ref>{{cite web|title=High Speed 1 Project Hoem|url=https://www.bechtel.com/projects/high-speed-1/|website=www.betchel.com|publisher=Betchel Corporation|access-date=8 February 2015}}</ref>
*130&nbsp;km – range of a [[Scud]]-A missile
*163&nbsp;km – length of the [[Suez Canal]]
*164&nbsp;km – length of the [[Danyang–Kunshan Grand Bridge]]
*213&nbsp;km – length of [[Paris Métro]]
*217&nbsp;km – length of the [[Grand Union Canal]]
*223&nbsp;km – length of the [[Madrid Metro]]
*300&nbsp;km – range of a Scud-B missile
*386&nbsp;km – altitude of the [[International Space Station]]
*408&nbsp;km – length of the [[London Underground]] (active track)
*460&nbsp;km – distance from [[London]] to [[Paris]]
*470&nbsp;km – distance from [[Dublin]] to [[London]] [[as the crow flies]]
*600&nbsp;km – range of a Scud-C missile
*600&nbsp;km – height above ground of the [[Hubble Space Telescope]]
*804.67&nbsp;km – (500 miles) distance of the [[Indy 500]] automobile race

===Geographical===
*42&nbsp;km – width of [[Singapore]]
*75&nbsp;km – width of [[Rhode Island]]
*111&nbsp;km – distance covered by one degree of [[latitude]] on Earth's surface
*120&nbsp;km – width of [[Brunei]]
*180&nbsp;km – distance between [[Mumbai]] and [[Nashik]]
*200&nbsp;km – width of [[Qatar]]
*203&nbsp;km – length of [[Sognefjorden]], the third-largest [[fjord]] in the world
*220&nbsp;km – distance between [[Pune]] and Nashik
*240&nbsp;km – width of [[Rwanda]]
*240&nbsp;km – widest width of the [[English Channel]]
*400&nbsp;km – width of [[West Virginia]]
*430&nbsp;km – length of the [[Pyrenees]]
*450&nbsp;km – length of the [[Grand Canyon]]
*500&nbsp;km – widest width of [[Geography of Sweden|Sweden]] from east to west
*501&nbsp;km – width of [[Uganda]]
*550&nbsp;km – distance from [[San Francisco]] to [[Los Angeles]] [[as the crow flies]]
*560&nbsp;km – distance of [[Bordeaux–Paris]], formerly{{When|date=April 2010}} the longest one-day professional cycling race<ref name="cyclingrace">{{cite web|title=Bordeaux-Paris &#124; the event|url=http://www.bordeauxparis.com/en/the-event/|website=www.bordeauxparis.com|access-date=30 April 2017|archive-url=https://web.archive.org/web/20170328181843/http://www.bordeauxparis.com/en/the-event/|archive-date=28 March 2017|url-status=dead}}</ref>
*590&nbsp;km – length of land boundary between [[Geography of Finland|Finland]] and [[Geography of Sweden|Sweden]]
*724&nbsp;km – length of the [[Om River]]
*800&nbsp;km – width of [[Germany]]
*871&nbsp;km – distance from [[Sydney]] to [[Melbourne]] (along the [[Hume Highway]])
*897&nbsp;km – length of the [[River Douro]]
*900&nbsp;km – distance from [[Berlin]] to [[Stockholm]]
*956&nbsp;km – distance from [[Washington, D.C.]], to [[Chicago]], Illinois, [[as the crow flies]]
*970&nbsp;km – distance from [[Land's End to John o' Groats]] [[as the crow flies]]

===Astronomical===
*100&nbsp;km – the altitude at which the [[Fédération Aéronautique Internationale|FAI]] defines [[spaceflight]] to begin
*167&nbsp;km – diametre of [[Amalthea (moon)|Amalthea]], one of [[Jupiter]]'s inner moons
*200&nbsp;km – width of [[Valles Marineris]]
*220&nbsp;km – diametre of [[Phoebe (moon)|Phoebe]], the largest of [[Saturn]]'s outer moons
*300&nbsp;km – the approximate distance travelled by light in one [[millisecond]]
*340&nbsp;km – diametre of [[Nereid (moon)|Nereid]], the third-largest moon of [[Neptune]] which has a highly [[Elliptic orbit|elliptical orbit]]
*350&nbsp;km – lower bound of [[Low Earth orbit]]
*420&nbsp;km – diametre of [[Proteus (moon)|Proteus]], the second-largest moon of Neptune
*468&nbsp;km – diametre of the [[asteroid]] [[4 Vesta]]
*472&nbsp;km – diametre of [[Miranda (moon)|Miranda]], one of [[Uranus]]'s major moons
*974.6&nbsp;km – greatest diametre of [[Ceres (dwarf planet)|1 Ceres]],<ref name="ReferenceB"/> the largest Solar System [[asteroid]]<ref name="Asteroid-planet?" group=note/>

==1 megametre==
[[File:1e6m comparison Mars Mercury Moon Pluto Haumea - no transparency.png|thumb|Small planets, the [[Moon]] and [[dwarf planet]]s in the Solar System have diametres from one to ten million metres. Top row: [[Mars]] (left), [[Mercury (planet)|Mercury]] (right); bottom row: [[Moon]] (left), [[Pluto]] (center), and [[Haumea (dwarf planet)|Haumea]] (right), to scale.]]

The ''{{vanchor|megametre}}'' ([[SI]] symbol: ''{{vanchor|Mm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{gaps|1|000|000}}&nbsp;[[metre|metre]]s (10<sup>6</sup>&nbsp;m). 
To help compare different [[orders of magnitude]], this section lists [[length]]s starting at 10<sup>6</sup> [[metre|m]] ([[#1 megametre|1 Mm]] or 1,000 [[kilometre|km]]).

=== Conversions ===
1 megametre is equal to:
* 1000 km
* {{val|e=6|u=m}} (one million metres)
* approximately 621.37 [[mile]]s

===Human-defined scales and structures===
*2.100 Mm – length of proposed [[Iran-Pakistan-India gas pipe]]
*2.100 Mm – distance from [[Casablanca]] to [[Rome]]
*2.288 Mm – length of the official [[Alaska Highway]] when it was built in the 1940s<ref>{{cite web|title=FAQ-Alaska Highway Facts|publisher=The MILEPOST|url=http://www.milepost.com/faq/hwy_drivingfacts.shtml|archive-url=https://web.archive.org/web/20070929182939/http://www.milepost.com/faq/hwy_drivingfacts.shtml|archive-date=29 September 2007|quote=1,390 miles ... Alaska Route 2 and often treated as a natural extension of the Alaska Highway|access-date=25 August 2007}}</ref>
*3.069 Mm – length of [[Interstate 95]] (from [[Houlton, Maine]], to [[Miami]], Florida)
*3.846 Mm – length of [[U.S. Route 1]] (from [[Fort Kent, Maine]], to [[Key West, Florida]])
*5.000 Mm – width of the [[United States]]
*5.007 Mm – estimated length of [[Interstate 90]] (Seattle, Washington, to Boston, Massachusetts)
*5.614 Mm – length of the Australian [[Dingo Fence]]<ref>{{cite encyclopedia|first1=R.J.|last1=Downward|last2=Bromell|first2=J.E.|chapter=The development of a policy for the management of dingo populations in South Australia|title=Proceedings of the Fourteenth Vertebrate Pest Conference 1990|publisher=[[University of Nebraska–Lincoln]]|date=March 1990|chapter-url=http://digitalcommons.unl.edu/vpc14/23/|access-date=31 August 2009|archive-url=https://archive.today/20240524113343/https://www.webcitation.org/5jXGkvGsS?url=http://digitalcommons.unl.edu/vpc14/23/|archive-date=24 May 2024|url-status=live}}</ref>
*6.371 Mm – global-average [[Earth radius]]
*6.4 Mm – length of the [[Great Wall of China]]
*7.821 Mm – length of the [[Trans-Canada Highway]], the world's longest national highway (from [[Victoria, British Columbia]], to [[St. John's, Newfoundland]])
*8.836 Mm – road distance between [[Prudhoe Bay]], Alaska, and [[Key West, Florida]], the endpoints of the U.S. road network
*8.852 Mm – aggregate length of the [[Great Wall of China]], including trenches, hills and rivers<ref>{{cite web|url=https://www.google.com/hostednews/afp/article/ALeqM5hZntU8l3vH1I21vcievtc-QIryLA|title=China's Great Wall far longer than thought: survey|publisher=[[Agence France-Presse|AFP]]|date=20 April 2009|access-date=20 April 2009|archive-url=https://web.archive.org/web/20090427193631/https://www.google.com/hostednews/afp/article/ALeqM5hZntU8l3vH1I21vcievtc-QIryLA|archive-date=27 April 2009 |url-status=dead}}</ref>
*9.259 Mm – length of the [[Trans-Siberian railway]]<ref>[http://www.poezda.net/en/train_timetable?tr_code=898975%3A%C0 CIS railway timetable], route No. 002, Moscow-Vladivostok. [https://web.archive.org/web/20200406164311/https://www.poezda.net/en/train_timetable?tr_code=898975%3A%EF%BF%BD Archived] 3 December 2009.</ref>

===Sports===
*The [[Munda Biddi Trail]] in [[Western Australia]], [[Australia]], is over 1,000&nbsp;km long – the world's longest off-road cycle trail
*1.200 Mm – the length of the [[Paris–Brest–Paris]] bicycling event
*Several endurance auto races are, or were, run for 1,000&nbsp;km:
**[[Bathurst 1000]]
**[[1000 km Brands Hatch]]
**[[1000 km Buenos Aires]]
**[[1000 km Donington]]
**[[1000 km Monza]]
**[[1000 km Nürburgring]]
**[[1000 km Silverstone]]
**[[1000 km Spa]]
**[[1000 km Suzuka]]
**[[1000 km Zeltweg]]

===Geographical===
*1.010 Mm – distance from [[San Diego]] to [[El Paso]] [[as the crow flies]]
*1.100 Mm – length of [[Italy]]
*1.200 Mm – length of [[California]]
*1.200 Mm – width of [[Texas]]
*1.500 Mm – length of the [[Gobi Desert]]
*1.600 Mm – length of the [[Namib]], the oldest desert on Earth
*2.000 Mm – distance from [[Beijing]] to [[Hong Kong]] as the crow flies
*2.300 Mm – length of the [[Great Barrier Reef]]
*2.800 Mm – narrowest width of [[Atlantic Ocean]] (Brazil-West Africa)
*2.850 Mm – length of the [[Danube]] river
*2.205 Mm – length of [[Geography of Sweden|Sweden]]'s total land boundaries
*2.515 Mm – length of [[Geography of Norway|Norway]]'s total land boundaries
*3.690 Mm – length of the [[Volga]] river, longest in Europe
*4.000 Mm – length of the [[Kalahari Desert]]
*4.350 Mm – length of the [[Yellow River]]
*4.600 Mm – width of the [[Mediterranean Sea]]
*4.800 Mm – length of the [[Sahara]]
*4.800 Mm – widest width of [[Atlantic Ocean]] (U.S.-Northern Africa)
*5.100 Mm – distance from [[Dublin]] to [[New York City|New York]] as the crow flies
*6.270 Mm – length of the [[Mississippi River|Mississippi]]-[[Missouri River]] system
*6.380 Mm – length of the [[Yangtze River]]
*6.400 Mm – Length of the [[Amazon River]]
*6.758 Mm – Length of the [[Nile River|Nile]] system, longest on [[Earth]]
*8.200 Mm – Approximate Distance from [[Dublin]] to [[San Francisco]]

===Astronomical===
*1.000 Mm – estimated shortest axis of [[Ellipsoid|triaxial]] [[dwarf planet]] {{dp|Haumea}}
*1.186 Mm – diametre of [[Charon (moon)|Charon]], the largest moon of [[Pluto]]
*1.280 Mm – diametre of the trans-Neptunian object [[50000 Quaoar]]
*1.436 Mm – diametre of [[Iapetus (moon)|Iapetus]], one of [[Saturn]]'s major moons
*1.578 Mm – diametre of [[Titania (moon)|Titania]], the largest of [[Uranus]]'s moons
*1.960 Mm – estimated longest axis of [[Haumea (dwarf planet)|Haumea]]
*2.326 Mm – diametre of the dwarf planet [[Eris (dwarf planet)|Eris]], the largest [[trans-Neptunian object]] found to date
*2.376 Mm – diametre of [[Pluto]]
*2.707 Mm – diametre of [[Triton (moon)|Triton]], largest moon of [[Neptune]]
*3.122 Mm – diametre of [[Europa (moon)|Europa]], the smallest [[Galilean satellite]] of [[Jupiter]]
*3.476 Mm – diametre of [[Earth]]'s [[Moon]]
*3.643 Mm – diametre of [[Io (moon)|Io]], a moon of Jupiter
*4.821 Mm – diametre of [[Callisto (moon)|Callisto]], a moon of Jupiter
*4.879 Mm – diametre of [[Mercury (planet)|Mercury]]
*5.150 Mm – diametre of [[Titan (moon)|Titan]], the largest moon of Saturn
*5.262 Mm – diametre of Jupiter's moon [[Ganymede (moon)|Ganymede]], the largest moon in the [[Solar System]]
*6.371 Mm – [[Earth radius|radius of Earth]]
*6.792 Mm – diametre of [[Mars]]

==10 megametres==
[[File:1e7m comparison Uranus Neptune Sirius B Earth Venus.png|thumb|Planets from Venus up to Uranus have diametres from ten to one hundred million metres. Top row: [[Uranus]] (left), [[Neptune]] (right); middle row: [[Earth]] (left), [[Sirius B]] (center), and [[Venus]] (right), to scale.]]

{{More citations needed section|date=April 2007}}
To help compare different [[orders of magnitude]], this section lists [[length]]s starting at 10<sup>7</sup> [[metre|metre]]s ([[#10 megametre|10 megametres]] or 10,000 [[kilometre|kilometre]]s).

===Conversions===
10 megametres (10 Mm) is
*6,215 [[mile]]s
*side of a [[square (geometry)|square]] of area 100,000,000 [[square kilometre|square kilometre]]s (km<sup>2</sup>)
*radius of a [[circle]] of area 314,159,265&nbsp;km<sup>2</sup>

===Human-defined scales and structures===

*11.085 Mm – length of the [[Kyiv]]-[[Vladivostok]] railway, a longer variant of the [[Trans-Siberian railway]]<ref>[http://www.poezda.net/en/train_timetable?tr_code=907081%3A%D4 CIS railway timetable], route No. 350, Kyiv-Vladivostok. [https://web.archive.org/web/20200406164332/https://www.poezda.net/en/train_timetable?tr_code=907081%3A%EF%BF%BD Archived] 3 December 2009.</ref>
*13.300 Mm – length of roads rehabilitated and widened under the [[National Highway Development Project]] (launched in 1998) in [[India]]
*39.000 Mm – length of the [[SEA-ME-WE 3]] optical submarine telecommunications cable, joining 39 points between [[Norden, Lower Saxony|Norden]], Germany, and [[Okinawa Prefecture|Okinawa]], Japan
*67.000 Mm – total length of [[National highways of India|National Highways in India]]
*80.000 Mm – 20,000 (metric, French) [[league (unit)|leagues]] (see [[Jules Verne]], ''[[Twenty Thousand Leagues Under the Seas]]'')

===Geographical===
*10 Mm – approximate altitude of the outer boundary of the [[exosphere]]
*10.001 Mm – length of the [[meridian arc]] from the [[North Pole]] to the [[Equator]] (the original definition of the [[metre|metre]] was based on this length)
*40.000 Mm – length of the [[Ring of Fire]]
*60.000 Mm – total length of the [[mid-ocean ridge]]s

===Astronomical===
*12.000 Mm – diametre of [[Sirius|Sirius B]], a [[white dwarf]]<ref>{{cite news|first=Christine|last=McGourty
|title=Hubble finds mass of white dwarf
|work=BBC News|date=14 December 2005
|url=http://news.bbc.co.uk/2/hi/science/nature/4528586.stm
|access-date=13 October 2007}}</ref>
*12.104 Mm – diametre of [[Venus]]
*12.742 Mm – diametre of [[Earth]]
*12.900 Mm – minimum distance of the [[meteoroid]] {{mpl|2004 FU|162}} from the centre of Earth on 31 March 2004, closest on record
*14.000 Mm – smallest diametre of Jupiter's [[Great Red Spot]]
*19.000 Mm – separation between [[Pluto]] and [[Charon (moon)|Charon]]
*30.8568 Mm – 1 nanoparsec
*34.770 Mm – minimum distance of the [[asteroid]] [[99942 Apophis]] on 13 April 2029 from the centre of Earth
*35.786 Mm – altitude of [[geostationary orbit]]
*40.005 Mm – polar circumference of the Earth
*40.077 Mm – equatorial circumference of the Earth
*49.528 Mm – diametre of [[Neptune]]
*51.118 Mm – diametre of [[Uranus]]

==100 megametres==
[[File:1e8m comparison Saturn Jupiter OGLE-TR-122b with Uranus Neptune Sirius B Earth Venus no transparency.png|thumb|The [[Earth]]-[[Moon]] orbit, [[Saturn]], [[OGLE-TR-122b]], [[Jupiter]], and [[1 E7 m|other objects]], to scale. Click on image for detailed view and links to other length scales.]]
[[File:Scale model of Solar System 10 billion to 1.svg|thumb|300px|Scale model at megametres of the main Solar System bodies]]

To help compare different [[orders of magnitude]], this section lists [[length]]s starting at 10<sup>8</sup> [[metre|metre]]s ([[#100 megametre|100 megametres]] or 100,000 [[kilometre|kilometre]]s or 62,150 [[mile]]s).

*102 Mm – diametre of [[HD 149026 b]], an unusually dense [[gas giant|Jovian planet]]
*115 Mm – width of Saturn's Rings
*120 Mm – diametre of [[EBLM J0555-57]]Ab, the smallest-known star
*120 Mm – diametre of [[Saturn]]
*142 Mm – diametre of [[Jupiter]], the largest planet in the [[Solar System]]
*170 Mm – diametre of [[TRAPPIST-1]], a star discovered to have seven planets around it
*174 Mm – diametre of [[OGLE-TR-122b]], one of the smallest known stars
*180 Mm – average distance covered during life
*215 Mm – diametre of [[Proxima Centauri]], the nearest star to the Solar System
*257 Mm – diametre of [[TrES-4b|TrES-4]], one of the largest exoplanets
*260 Mm – diametre of the [[Barnard's Star]]
*272 Mm – diametre of [[WASP-12b]]
*299.792 Mm – one [[light-second]]; the distance [[light]] travels in [[vacuum]] in one [[second]] (see [[speed of light]])
*314 Mm – diametre of [[CT Cha b]]
*384.4 Mm (238,855&nbsp;mi) – average [[Lunar distance (astronomy)|Earth–Moon distance]]<ref name="NASA-LD">{{cite web|author=NASA Staff|title=Solar System Exploration – Earth's Moon: Facts & Figures|url=http://solarsystem.nasa.gov/planets/profile.cfm?Display=Facts&Object=Moon|date=10 May 2011|publisher=[[NASA]]|access-date=6 November 2011|archive-url=https://web.archive.org/web/20111107170202/http://solarsystem.nasa.gov/planets/profile.cfm?Display=Facts&Object=Moon|archive-date=7 November 2011|url-status=dead}}</ref>
*671 Mm – separation between [[Jupiter]] and [[Europa (moon)|Europa]]
*696 Mm – [[Solar radius|radius]] of [[Sun]]
*989 Mm – diametre of [[Epsilon Indi]], one of the nearest stars to Earth

==1 gigametre==
[[File:Gigameter group.png|thumb|13 things in the gigametre group]]
[[File:1e9m comparison Gamma Orionis, Algol B, the Sun, and smaller - antialiased no transparency.png|thumb|Upper part: [[Bellatrix|Gamma Orionis]], [[Algol B]], the [[Sun]] (centre), and <span style="white-space:nowrap;">[[1 E8 m|other objects]]</span> to scale.]]

The ''{{vanchor|gigametre}}'' ([[SI]] symbol: ''{{vanchor|Gm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{gaps|1|000|000|000}}&nbsp;[[metre|metre]]s (10<sup>9</sup>&nbsp;m). 
To help compare different distances this section lists lengths starting at 10<sup>9</sup> [[metre|metre]]s (1 gigametre (Gm) or 1 billion [[metre|metre]]s).

*1.2 Gm – separation between [[Saturn]] and [[Titan (moon)|Titan]]
*1.39 Gm – diametre of [[Sun]]<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html|title=Sun Fact Sheet|website=nssdc.gsfc.nasa.gov}}</ref><ref>[http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html Sun Fact Sheet]</ref>
*1.5 Gm – orbit from Earth of the [[James Webb Space Telescope]]
*1.71 Gm – diametre of [[Alpha Centauri]] A, one of the closest stars.<ref>{{cite journal | arxiv=2104.10086 | doi=10.3847/1538-3881/abfaff | doi-access=free | title=Precision Millimetre Astrometry of the α Centauri AB System | date=2021 | last1=Akeson | first1=Rachel | last2=Beichman | first2=Charles | last3=Kervella | first3=Pierre | last4=Fomalont | first4=Edward | last5=Benedict | first5=G. Fritz | journal=The Astronomical Journal | volume=162 | issue=1 | page=14 | bibcode=2021AJ....162...14A }}</ref>
*2.19 Gm – closest approach of [[Comet Lexell]] to [[Earth]], happened on 1 July 1770; closest [[comet]] approach on record
*2.38 Gm – diametre of [[Sirius]] A, brightest naked eye star.<ref>{{cite journal | arxiv=astro-ph/0507523 | doi=10.1086/462419 | title=The Age and Progenitor Mass of Sirius B | date=2005 | last1=Liebert | first1=James | last2=Young | first2=Patrick A. | last3=Arnett | first3=David | last4=Holberg | first4=J. B. | last5=Williams | first5=Kurtis A. | journal=The Astrophysical Journal | volume=630 | issue=1 | pages=L69–L72 | bibcode=2005ApJ...630L..69L | s2cid=8792889 }}</ref>
*3 Gm – total length of "wiring" in the human brain<ref>Neuroscience: The Science of the Brain{{cite web|url=http://www.braincampaign.org/Pub/Pub_Main_Display.asp?LC_Docs_ID%3D2769|title=IBRO Brain Campaign|access-date=8 June 2011|url-status=dead|archive-url=https://web.archive.org/web/20110202081347/http://www.braincampaign.org/Pub/Pub_Main_Display.asp?LC_Docs_ID=2769|archive-date=2 February 2011}} p.44</ref>
*3.5 Gm – diametre of [[Vega]]<ref>{{cite journal | doi=10.1088/0004-637X/708/1/71 | title=A New View of Vega's Composition, Mass, and Age | date=2010 | last1=Yoon | first1=Jinmi | last2=Peterson | first2=Deane M. | last3=Kurucz | first3=Robert L. | last4=Zagarello | first4=Robert J. | journal=The Astrophysical Journal | volume=708 | issue=1 | pages=71–79 | bibcode=2010ApJ...708...71Y | s2cid=120986935 | doi-access=free }}</ref>
*4.2 Gm – diametre of [[Algol B]]
*4.3 Gm – circumference of [[Sun]]
*5.0 Gm – closest approach of [[Comet Halley]] to Earth, happened on 10 April 837
*5.0 Gm – ''(proposed) Size of the arms of the giant triangle shaped Michelson interferometre of the [[Laser Interferometre Space Antenna]] (LISA) planned to start observations sometime in the 2030s.''
*7.9 Gm – diametre of [[Bellatrix|Gamma Orionis]], a blue dwarf or blue giant
*9.0 Gm – estimated diametre of the [[event horizon]] of [[Sagittarius A*]], the [[supermassive black hole]] in the center of the [[Milky Way]] galaxy

==10 gigametres==
[[File:1e10m comparison Rigel, Aldebaran, and smaller - antialiased no transparency.png|thumb|Rigel and Aldebaran (top left and right) compared to smaller stars, the Sun (very small dot in lower middle, with orbit of Mercury as yellow ellipse) and transparent sphere with radius of one light-minute]]
To help compare different [[distance]]s this section lists lengths starting at 10<sup>10</sup> [[metre|metre]]s (10 [[1 gigametre|gigametre]]s (Gm) or 10 million [[kilometre|kilometre]]s, or 0.07 [[astronomical unit]]s).

*10.4 Gm – diametre of Spica, an oval-shaped blue giant star and a [[List of supernova candidates|nearby supernova candidate]].<ref name="Tkachenko2016">{{citation |last1=Tkachenko |first1=A. |title=Stellar modelling of Spica, a high-mass spectroscopic binary with a β Cep variable primary component |date=May 2016 |journal=Monthly Notices of the Royal Astronomical Society |volume=458 |issue=2 |pages=1964–1976 |arxiv=1601.08069 |bibcode=2016MNRAS.458.1964T |doi=10.1093/mnras/stw255 |s2cid=26945389 |display-authors=1 |last2=Matthews |first2=J. M. |last3=Aerts |first3=C. |last4=Pavlovski |first4=K. |last5=Pápics |first5=P. I. |last6=Zwintz |first6=K. |last7=Cameron |first7=C. |last8=Walker |first8=G. A. H. |last9=Kuschnig |first9=R. |doi-access=free |last10=Degroote |first10=P. |last11=Debosscher |first11=J. |last12=Moravveji |first12=E. |last13=Kolbas |first13=V. |last14=Guenther |first14=D. B. |last15=Moffat |first15=A. F. J. |last16=Rowe |first16=J. F. |last17=Rucinski |first17=S. M. |last18=Sasselov |first18=D. |last19=Weiss |first19=W. W.}}</ref>
*12.6 Gm – diametre of [[Pollux (star)|Pollux]], the closest [[red giant]] [[star]] to the Sun.<ref name=":2">{{cite journal | arxiv=1712.08109 | doi=10.3847/1538-3881/aa9d8b | doi-access=free | title=Fundamental Parametres of 87 Stars from the Navy Precision Optical Interferometre | date=2017 | last1=Baines | first1=Ellyn K. | last2=Armstrong | first2=J. Thomas | last3=Schmitt | first3=Henrique R. | last4=Zavala | first4=R. T. | last5=Benson | first5=James A. | last6=Hutter | first6=Donald J. | last7=Tycner | first7=Christopher | last8=Belle | first8=Gerard T. van | journal=The Astronomical Journal | volume=155 | issue=1 | page=30 | bibcode=2018AJ....155...30B }}</ref> It is a [[red clump]] star fusing helium into carbon at its core.<ref name="howes">{{Cite journal |last1=Howes |first1=Louise M. |last2=Lindegren |first2=Lennart |last3=Feltzing |first3=Sofia |last4=Church |first4=Ross P. |last5=Bensby |first5=Thomas |date=2019-02-01 |title=Estimating stellar ages and metallicities from parallaxes and broadband photometry: successes and shortcomings |url=https://www.aanda.org/articles/aa/abs/2019/02/aa33280-18/aa33280-18.html |journal=Astronomy & Astrophysics |language=en |volume=622 |pages=A27 |doi=10.1051/0004-6361/201833280 |arxiv=1804.08321 |bibcode=2019A&A...622A..27H |issn=0004-6361}}</ref>
*15 Gm – closest distance of [[Comet Hyakutake]] from [[Earth]]
*18 Gm – one [[light-minute]] (see yellow sphere in right-hand diagram)
*24 Gm – radius of a [[heliostationary orbit]]
*30.8568 Gm – 1 microparsec
*35 Gm – approximate diametre of [[Arcturus]], a close red giant star.<ref>{{cite journal | arxiv=1109.4425 | doi=10.1088/0004-637X/743/2/135 | title=Fundamental Parametres and Chemical Composition of Arcturus | date=2011 | last1=Ramírez | first1=I. | last2=Allende Prieto | first2=C. | journal=The Astrophysical Journal | volume=743 | issue=2 | page=135 | bibcode=2011ApJ...743..135R | s2cid=119186472 }}</ref> It is on the [[red giant branch]], fusing hydrogen into helium in a shell surrounding an inert helium core.<ref name="howes" />
*46 Gm – [[Apsis|perihelion]] distance of [[Mercury (planet)|Mercury]] (yellow ellipse on the right)
*55 Gm – 60,000-year [[perigee]] of [[Mars]] (last achieved on 27 August 2003)
*58 Gm – average passing distance between [[Earth]] and Mars at the moment they overtake each other in their orbits
*61 Gm – diametre of [[Aldebaran]], a red giant branch star (large star on right)<ref name="aldiam">{{Cite journal |last1=Richichi |first1=A. |last2=Roccatagliata |first2=V. |last3=Shultz |first3=Matt |last4=Williamson |first4=Michael H. |last5=Moya |first5=Andres |year=2005 |title=Aldebaran's angular diametre: How well do we know it? |journal=Astronomy & Astrophysics |volume=433 |issue=1 |pages=305–312 |arxiv=astro-ph/0502181 |bibcode=2005A&A...433..305R |doi=10.1051/0004-6361:20041765 |s2cid=119414301}} They derived an angular diametre of 20.58±0.03 milliarcsec, which given a distance of 65 light-years yields a diametre of 61 million km.</ref>
*70 Gm – [[Apsis|aphelion]] distance of Mercury
*76 Gm – [[Neso (moon)|Neso]]'s [[apsis|apocentric]] distance; greatest distance of a [[natural satellite]] from its parent [[planet]] ([[Neptune]])

==100 gigametres==
[[File:1e11m comparison R Doradus and Betelgeuse, and smaller - antialiased no transparency.png|thumb|From largest to smallest: Jupiter's orbit, red supergiant star Betelgeuse, Mars' orbit, Earth's orbit, star R Doradus, and orbits of Venus, Mercury. Inside R Doradus's depiction are the blue supergiant star Rigel and red giant star Aldebaran. The faint yellow glow around the Sun represents one light-minute. Click image to see more details and links to their scales.]]
To help compare distances at different [[orders of magnitude]] this section lists lengths starting at 10<sup>11</sup> [[metre|metre]]s (100 [[#1 gigametre|gigametre]] or 100 million [[kilometre|kilometre]]s or 0.7 [[astronomical unit]]s).

*103 Gm (0.69 au) – diametre of [[Rigel]]<ref name=":2" />
*109 Gm (0.7 au) – distance between Venus and the Sun
*149.6 Gm (93.0 million mi; 1.0 au) – average distance between the [[Earth]] and the Sun – the original definition of the [[astronomical unit]]
*199 Gm (1.3 au) – diametre of [[Rho Persei]], an [[asymptotic giant branch]] star, fusing carbon into neon in a shell surrounding an inert core.<ref>{{Cite journal |last1=Kallinger |first1=T. |last2=Beck |first2=P. G. |last3=Hekker |first3=S. |last4=Huber |first4=D. |last5=Kuschnig |first5=R. |last6=Rockenbauer |first6=M. |last7=Winter |first7=P. M. |last8=Weiss |first8=W. W. |last9=Handler |first9=G. |last10=Moffat |first10=A. F. J. |last11=Pigulski |first11=A. |last12=Popowicz |first12=A. |last13=Wade |first13=G. A. |last14=Zwintz |first14=K. |date=April 2019 |title=Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE - Constellation |journal=Astronomy & Astrophysics |volume=624 |pages=A35 |doi=10.1051/0004-6361/201834514 |arxiv=1902.07531 |bibcode=2019A&A...624A..35K |issn=0004-6361}}</ref>
*228 Gm (1.5 au) – distance between [[Mars]] and the Sun
*248 Gm (1.7 au) – diametre of [[Enif]], a small [[red supergiant]] star in the constellation [[Pegasus (constellation)|Pegasus]]<ref>{{Cite journal |last1=McDonald |first1=Iain |last2=Zijlstra |first2=Albert A. |last3=Watson |first3=Robert A. |date=2017-10-11 |title=Fundamental parametres and infrared excesses of Tycho-Gaia stars |journal=Monthly Notices of the Royal Astronomical Society |volume=471 |issue=1 |pages=770–791 |doi=10.1093/mnras/stx1433 |doi-access=free |arxiv=1706.02208 |issn=0035-8711}}</ref>
*280 Gm (1.9 au) – diametre of [[Deneb]], a blue supergiant and the brightest star in the [[Cygnus (constellation)|Cygnus constellation]]<ref>{{cite journal | arxiv=1007.2095 | doi=10.1051/0004-6361/201014509 | title=Time, spatial, and spectral resolution of the H ''α'' line-formation region of Deneb and Rigel with the VEGA/CHARA interferometre | date=2010 | last1=Chesneau | first1=O. | last2=Dessart | first2=L. | last3=Mourard | first3=D. | last4=Bério | first4=Ph. | last5=Buil | first5=Ch. | last6=Bonneau | first6=D. | last7=Borges Fernandes | first7=M. | last8=Clausse | first8=J. M. | last9=Delaa | first9=O. | last10=Marcotto | first10=A. | last11=Meilland | first11=A. | last12=Millour | first12=F. | last13=Nardetto | first13=N. | last14=Perraut | first14=K. | last15=Roussel | first15=A. | last16=Spang | first16=A. | last17=Stee | first17=P. | last18=Tallon-Bosc | first18=I. | last19=McAlister | first19=H. | last20=Ten Brummelaar | first20=T. | last21=Sturmann | first21=J. | last22=Sturmann | first22=L. | last23=Turner | first23=N. | last24=Farrington | first24=C. | last25=Goldfinger | first25=P. J. | journal=Astronomy and Astrophysics | volume=521 | pages=A5 | bibcode=2010A&A...521A...5C | s2cid=10340205 }}</ref>
*511 Gm (3.4 au) – average diametre of [[Mira]], a pulsating red giant and the progenitor of the [[Mira variables]]. It is an [[asymptotic giant branch]] star.<ref>{{Cite journal |last1=Woodruff |first1=H. C. |last2=Eberhardt |first2=M. |last3=Driebe |first3=T. |last4=Hofmann |first4=K.-H. |last5=Ohnaka |first5=K. |last6=Richichi |first6=A. |last7=Schertl |first7=D. |last8=Schoeller |first8=M. |last9=Scholz |first9=M. |last10=Weigelt |first10=G. |last11=Wittkowski |first11=M. |last12=Wood |first12=P. R. |date=July 2004 |title=Interferometric observations of the Mira star o Ceti with the VLTI/VINCI instrument in the near-infrared |journal=Astronomy & Astrophysics |volume=421 |issue=2 |pages=703–714 |doi=10.1051/0004-6361:20035826 |arxiv=astro-ph/0404248 |bibcode=2004A&A...421..703W |issn=0004-6361}}</ref>
*570 Gm (3.8 au) – length of the tail of [[Comet Hyakutake]] measured by ''[[Ulysses (spacecraft)|Ulysses]]''; the actual value could be much higher
*590 Gm (3.9 au) – diametre of the [[Pistol Star]], a blue [[hypergiant]] star<ref>{{cite journal | arxiv=1403.5298 | doi=10.1088/0004-637X/785/2/120 | title=Nature Versus Nurture: Luminous Blue Variable Nebulae in and Near Massive Stellar Clusters at the Galactic Center | date=2014 | last1=Lau | first1=R. M. | last2=Herter | first2=T. L. | last3=Morris | first3=M. R. | last4=Adams | first4=J. D. | journal=The Astrophysical Journal | volume=785 | issue=2 | page=120 | bibcode=2014ApJ...785..120L | s2cid=118447462 }}</ref>
*591 Gm (4.0 au) – minimum distance between the [[Earth]] and [[Jupiter]]
*780 Gm (5.2 au) – average distance between Jupiter and the Sun
*785 Gm (5.25 au) – diametre of [[Rho Cassiopeiae]], a rare [[yellow hypergiant]] star<ref>{{Cite arXiv |last1=Anugu |first1=Narsireddy |last2=Baron |first2=Fabien |last3=Monnier |first3=John D. |last4=Gies |first4=Douglas R. |last5=Roettenbacher |first5=Rachael M. |last6=Schaefer |first6=Gail H. |last7=Montargès |first7=Miguel |last8=Kraus |first8=Stefan |last9=Bouquin |first9=Jean-Baptiste Le |date=2024-08-05 |title=CHARA Near-Infrared Imaging of the Yellow Hypergiant Star $\rho$ Cassiopeiae: Convection Cells and Circumstellar Envelope |class=astro-ph.SR |eprint=2408.02756v2 |language=en}}</ref>
*947 Gm (6.4 au) – diametre of [[Antares|Antares A]]
*965 Gm (6.4 au) – maximum distance between the Earth and Jupiter

==1 terametre==
[[File:Terameter group.png|thumb|Eight things in the terametre group]]
[[File:1e12m comparison Kuiper belt and smaller.png|thumb|Comparison of size of the Kuiper belt (large faint torus) with the star VY Canis Majoris (within Saturn's orbit), Betelgeuse (inside Jupiter's orbit) and R Doradus (small central red sphere) together with the orbits of Neptune and Uranus, to scale. The yellow ellipses represent the orbits of each planet and the dwarf planet Pluto.]]

The ''{{vanchor|terametre}}'' ([[SI]] symbol: ''{{vanchor|Tm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to {{gaps|1|000|000|000|000}}&nbsp;[[metre|metre]]s (10<sup>12</sup>&nbsp;m). 
To help compare different [[distance]]s, this section lists lengths starting at 10<sup>12</sup> [[metre|m]] (1 [[#1 terametre|Tm]] or 1 billion [[kilometre|km]] or 6.7 [[astronomical unit]]s).

*≈1 Tm – 6.7 au – diametre of the red supergiant [[Betelgeuse]] based on multiple angular diametre estimates<ref>{{cite journal | arxiv=2006.09837 | doi=10.3847/1538-4357/abb8db | doi-access=free | title=Standing on the Shoulders of Giants: New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA | date=2020 | last1=Joyce | first1=Meridith | last2=Leung | first2=Shing-Chi | last3=Molnár | first3=László | last4=Ireland | first4=Michael | last5=Kobayashi | first5=Chiaki | last6=Nomoto | first6=Ken'Ichi | journal=The Astrophysical Journal | volume=902 | issue=1 | page=63 | bibcode=2020ApJ...902...63J }}</ref>
*1.032 Tm – 6.9 au – diametre of the blue hypergiant [[Eta Carinae]] (at optical depth 2/3)<ref>{{Cite journal |last1=Gull |first1=Theodore R. |last2=Hillier |first2=D. John |last3=Hartman |first3=Henrik |last4=Corcoran |first4=Michael F. |last5=Damineli |first5=Augusto |last6=Espinoza-Galeas |first6=David |last7=Hamaguchi |first7=Kenji |last8=Navarete |first8=Felipe |last9=Nielsen |first9=Krister |last10=Madura |first10=Thomas |last11=Moffat |first11=Anthony F. J. |last12=Morris |first12=Patrick |last13=Richardson |first13=Noel D. |last14=Russell |first14=Christopher M. P. |last15=Stevens |first15=Ian R. |date=July 2022 |title=Eta Carinae: An Evolving View of the Central Binary, Its Interacting Winds and Its Foreground Ejecta |journal=The Astrophysical Journal |language=en |volume=933 |issue=2 |pages=175 |doi=10.3847/1538-4357/ac74c2 |doi-access=free |arxiv=2205.15116 |bibcode=2022ApJ...933..175G |issn=0004-637X}}</ref>
*1.079 Tm – 7.2 au – one [[light-hour]]
*1.114 Tm – 7.5 au – diametre of [[WOH G64]], a star in the [[Large Magellanic Cloud]], which recently transformed from a red hypergiant to a yellow hypergiant<ref>{{Citation |last1=Munoz-Sanchez |first1=G. |title=The dramatic transition of the extreme Red Supergiant WOH G64 to a Yellow Hypergiant |date=2024-12-02 |arxiv=2411.19329 |last2=Kalitsounaki |first2=M. |last3=Wit |first3=S. de |last4=Antoniadis |first4=K. |last5=Bonanos |first5=A. Z. |last6=Zapartas |first6=E. |last7=Boutsia |first7=K. |last8=Christodoulou |first8=E. |last9=Maravelias |first9=G.}}</ref>
*1.4 Tm – 9.5 au – average distance between [[Saturn]] and the [[Sun]]
*1.47 Tm – 9.9 au – diametre of [[HR 5171 A]], a [[yellow hypergiant]] star.<ref>{{cite journal |last1=van Genderen |first1=A. M. |last2=Lobel |first2=A. |last3=Nieuwenhuijzen |first3=H. |last4=Henry |first4=G. W. |last5=De Jager |first5=C. |last6=Blown |first6=E. |last7=Di Scala |first7=G. |last8=Van Ballegoij |first8=E. J. |year=2019 |title=Pulsations, eruptions, and evolution of four yellow hypergiants |journal=Astronomy and Astrophysics |volume=631 |pages=A48 |arxiv=1910.02460 |bibcode=2019A&A...631A..48V |doi=10.1051/0004-6361/201834358 |s2cid=203836020}}</ref>
*1.5 Tm – 10 au – estimated diametre of [[VV Cephei A]], a red hypergiant with a blue dwarf companion.<ref name=bauer2008>{{cite journal|last1=Bauer|first1=W. H.|last2=Gull|first2=T. R.|last3=Bennett|first3=P. D.|doi=10.1088/0004-6256/136/3/1312|title=Spatial Extension in the Ultraviolet Spectrum of Vv Cephei|journal=The Astronomical Journal|volume=136|issue=3|pages=1312|year=2008|bibcode=2008AJ....136.1312H|s2cid=119404901 |doi-access=free}}</ref>
*1.75 Tm – 11.7 au – estimated diametre of [[Mu Cephei]], a red supergiant (possibly hypergiant) among the [[List of largest stars|largest-known stars]].<ref name="levesqueetal20052">Table 4 in {{cite journal |author1=Emily M. Levesque |author1-link=Emily Levesque |author2=Philip Massey |author3=K. A. G. Olsen |author4=Bertrand Plez |author5=Eric Josselin |author6=Andre Maeder |author7=Georges Meynet |name-list-style=amp |year=2005 |title=The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought |journal=The Astrophysical Journal |volume=628 |issue=2 |pages=973–985 |arxiv=astro-ph/0504337 |bibcode=2005ApJ...628..973L |doi=10.1086/430901 |s2cid=15109583}}</ref>
*2 Tm – 13.2 au – estimated diametre of [[VY Canis Majoris]], a red hypergiant that is among the [[list of largest stars|largest-known stars]]<ref name=":0">{{cite journal | arxiv=1512.01529 | doi=10.3847/0004-6256/151/3/51 | doi-access=free | title=SEARCHING FOR COOL DUST IN THE MID-TO-FAR INFRARED: THE MASS-LOSS HISTORIES OF THE HYPERGIANTS ''μ'' Cep, VY CMa, IRC+10420, AND ''ρ'' Cas | date=2016 | last1=Shenoy | first1=Dinesh | last2=Humphreys | first2=Roberta M. | last3=Jones | first3=Terry J. | last4=Marengo | first4=Massimo | last5=Gehrz | first5=Robert D. | last6=Helton | first6=L. Andrew | last7=Hoffmann | first7=William F. | last8=Skemer | first8=Andrew J. | last9=Hinz | first9=Philip M. | journal=The Astronomical Journal | volume=151 | issue=3 | page=51 | bibcode=2016AJ....151...51S }}</ref><ref name="Wittkowski_vlti">{{cite journal|doi=10.1051/0004-6361/201219126|last1=Wittkowski|first1=M.|last2=Hauschildt|first2=P.H.|last3=Arroyo-Torres|first3=B.|last4=Marcaide|first4=J.M.|title=Fundamental properties and atmospheric structure of the red supergiant VY CMa based on VLTI/AMBER spectro-interferometry|journal=Astronomy & Astrophysics|volume=540|pages=L12|date=5 April 2012|bibcode=2012A&A...540L..12W|arxiv=1203.5194|s2cid=54044968}}</ref>
*2.142 Tm – 14.3 au – estimated diametre of [[WOH G64]], prior to its transformation into a yellow hypergiant.
*2.9 Tm – 19.4 au – average distance between [[Uranus]] and the Sun
*4.4 Tm – 29.4 au – [[Apsis|perihelion]] distance of [[Pluto]]
*4.5 Tm – 30.1 au – average distance between [[Neptune]] and the Sun
*4.5 Tm – 30.1 au – inner radius of the [[Kuiper belt]]
*5.7 Tm – 38.1 au – perihelion distance of [[136199 Eris|Eris]]
*6.0 Tm – 40.5 au – distance from [[Earth]] at which the [[Pale Blue Dot]] photograph was taken.
*7.3 Tm – 48.8 au – [[Apsis|aphelion]] distance of [[Pluto]]
*7.5 Tm – 50.1 au – outer boundary of the [[Kuiper Belt]]

==10 terametres==
[[File:1e13m comparison Hale Bopp and smaller - HQ no transparency.png|thumb|Sedna's orbit (left) is longer than 100 Tm, but other lengths are between 10 and 100 Tm: [[Comet Hale-Bopp]]'s orbit (lower, faint orange); one [[light-day]] (yellow spherical shell with yellow Vernal point arrow as radius); the heliosphere's [[termination shock]] (blue shell); and other arrows show positions of ''[[Voyager 1]]'' (red) and [[Pioneer 10]] (green). Click on image for larger view and links to other scales.]]
To help compare different [[distance]]s this section lists lengths starting at 10<sup>13</sup> [[metre|m]] (10 [[#1 terametre|Tm]] or 10 billion [[kilometre|km]] or 67 [[astronomical unit]]s).
*10 Tm – 67 AU – diametre of a hypothetical [[quasi-star]]
*11.1 Tm – 74.2 AU – distance that ''[[Voyager 1]]'' began detecting returning particles from [[termination shock]]
*11.4 Tm – 76.2 AU – [[Apsis|perihelion]] distance of [[90377 Sedna]]
*12.1 Tm – 70 to 90 AU – distance to [[termination shock]] (''Voyager 1'' crossed at 94 AU)
*12.9 Tm – 86.3 AU – distance to 90377 Sedna in March 2014
*13.2 Tm – 88.6 AU – distance to ''[[Pioneer 11]]'' in March 2014
*14.1 Tm – 94.3 AU – estimated radius of the [[Solar System]]
*14.4 Tm – 96.4 AU – distance to [[136199 Eris|Eris]] in March 2014 (now near its [[apsis|aphelion]])
*15.1 Tm – 101 AU – distance to [[Heliosphere#Heliosheath|heliosheath]]
*16.5 Tm – 111 AU – distance to ''[[Pioneer 10]]'' as of March 2014
*16.6 Tm – 111.2 AU – distance to ''[[Voyager 2]]'' as of May 2016
*18 Tm – 123.5 AU – distance between the [[Sun]] to the farthest dwarf planet in the Solar System, the Farout [[2018 VG18]]
*20.0 Tm – 135 AU – distance to ''[[Voyager 1]]'' as of May 2016
*20.6 Tm – 138 AU – distance to ''Voyager 1'' as of late February 2017
*21.1 Tm – 141 AU – distance to ''Voyager 1'' as of November 2017
*24.8 Tm – 166 AU – distance to ''Voyager 1'' as of November 2024
*25.9 Tm – 173 AU – one [[light-day]]
*30.8568 Tm – 206.3 AU – 1 milliparsec
*55.7 Tm – 371 AU – aphelion distance of the [[comet]] [[Hale-Bopp]]

==100 terametres==
[[File:1e14m comparison light day week and month.png|thumb|The largest yellow sphere indicates one light month distance from the Sun. Click the image for larger view, more details and links to other scales.]]

{{Incomplete list|date=November 2012}}
To help compare different [[distance]]s this section lists lengths starting at 10<sup>14</sup> [[metre|m]] (100 [[#1 terametre|Tm]] or 100 billion [[kilometre|km]] or 670 [[astronomical unit]]s).

*140 Tm – 937 AU – [[Apsis|aphelion]] distance of [[90377 Sedna]]
*172 Tm – 1150 AU – [[Schwarzschild radius|Schwarzschild diametre]] of [[H1821+643]], one of the most massive [[black hole]]s known
*181 Tm – 1210 AU – one [[light-week]]
*308.568 Tm – 2063 AU – 1 centiparsec
*757 Tm – 5059 AU – radius of the [[Stingray Nebula]]<ref name="Parthasarathy2000">{{cite journal|last1=Parthasarathy|first1=M.|title=Birth and early evolution of planetary nebulae|journal=Bulletin of the Astronomical Society of India|year=2000|volume=28|pages=217–224|bibcode=2000BASI...28..217P}}</ref>
*777 Tm – 5180 AU – one [[light-month]]

==1 petametre==
[[File:1e15m comparison cat's eye nebula barnard 68 one light year.png|thumb|Largest circle with yellow arrow indicates one [[light-year]] from [[Sun]]; [[Cat's Eye Nebula]] on left and [[Barnard 68]] in middle are depicted in front of [[Comet 1910 A1]]'s orbit. Click image for larger view, details and links to other scales.]]

The ''{{vanchor|petametre}}'' ([[SI]] symbol: ''{{vanchor|Pm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10<sup>15</sup>&nbsp;[[metre|metre]]s. 
To help compare different [[distance]]s this section lists lengths starting at 10<sup>15</sup> [[metre|m]] (1 Pm or 1 trillion [[kilometre|km]] or 6685 [[astronomical unit]]s (AU) or 0.11 [[light-year]]s).

*1.0 Pm = 0.105702341 light-years
*1.9 Pm ± 0.5 Pm = 12,000 AU = 0.2 light-year radius of [[Cat's Eye Nebula]]'s inner core<ref name="Cat calc">radius = distance times sin(angular diametre/2) = 0.2 [[light-year]]. Distance = 3.3 ± 0.9 [[light-year|kly]]; angular diametre = 20 [[arcseconds]] {{Harv|Reed|Balick|Hajian|Klayton|1999}}</ref><ref>{{Cite journal
 | last1 = Reed
 | first1 = Darren S.
 | last2 = Balick
 | first2 = Bruce
 | last3 = Hajian
 | first3 = Arsen R.
 | last4 = Klayton
 | first4 = Tracy L.
 | last5 = Giovanardi
 | first5 = Stefano
 | last6 = Casertano
 | first6 = Stefano
 | last7 = Panagia
 | first7 = Nino
 | last8 = Terzian
 | first8 = Yervant
 | title = Hubble Space Telescope Measurements of the Expansion of NGC 6543: Parallax Distance and Nebular Evolution
 | journal = Astronomical Journal
 | year = 1999
 | volume = 118
 | issue = 5
 | pages = 2430–2441
 | bibcode = 1999AJ....118.2430R
 | doi = 10.1086/301091
 |arxiv = astro-ph/9907313 | s2cid = 14746840
 }}</ref>
*3.08568 Pm = 20,626 AU = 1 deciparsec
*4.7 Pm = 30,000 AU = half-light-year diametre of [[Bok globule]] [[Barnard 68]]<ref name="Szpir">{{cite web|first=Michael|last=Szpir|title=Bart Bok's Black Blobs|url=http://www.americanscientist.org/template/AssetDetail/assetid/14678|date=May–June 2001|archive-url=https://web.archive.org/web/20030629033609/http://www.americanscientist.org/template/AssetDetail/assetid/14678|archive-date=29 June 2003|publisher=[[American Scientist]]|quote=Bok globules such as Barnard 68 are only about half a light-year across and weigh in at about two solar masses|access-date=19 November 2008}}</ref>
*7.5 Pm – 50,000 AU – possible outer boundary of [[Oort cloud]] (other estimates are 75,000 to 125,000 or even 189,000 [[Astronomical unit|AU]] (1.18, 2, and 3 [[light-year]]s, respectively))
*9.5 Pm – 63,241.1 AU – one [[light-year]], the distance light travels in one year
*9.9 Pm – 66,000 AU – [[Apsis|aphelion]] distance of the [[C/1999 F1 (Catalina)]]

==10 petametres==
[[File:1e16m comparison ten light years bubble nebula.png|thumb|Objects with size order of magnitude 1e16m: Ten light-years (94.6 [[Petametre|Pm]]) radius circle with yellow Vernal Point arrow; Bubble Nebula (NGC 7635), left; Dumbbell Nebula (NGC 6853), right; one light-year shell lower right with the smaller Cat's Eye Nebula (NGC_6543) and Barnard 68 adjacent.]]
[[File:1e16m comparison 10 light years sirius.png|thumb|1e16m lengths: Ten light-years (94.6 [[Petametre|Pm]]) yellow shell; Sirius below right; BL Ceti below left; Proxima and Alpha Centauri upper right; light-year shell with Comet 1910 A1's orbit inside top right]]

To help compare different distances this section lists lengths starting at 10<sup>16</sup> [[metre|m]] (10 [[#1 petametre|Pm]] or 66,800 [[astronomical unit|AU]], 1.06 [[light-year]]s).

*15 Pm – 1.59 light-years – possible outer radius of [[Oort cloud]]
*20 Pm – 2.11 light-years – maximum extent of influence of the Sun's [[gravitational field]]{{Citation needed|reason=Where is this value from? The Sun's [[Hill sphere]] with respect to the galaxy is about 1.1 parsecs, per Chebotarev (1964)|date=January 2018}}
*30.9 Pm – 3.26 light-years – 1 [[parsec]]
*39.9 Pm – 4.22 light-years – distance to [[Proxima Centauri]] (nearest star to [[Sun]])
*81.3 Pm – 8.59 light-years – distance to [[Sirius]]
*94.6 Pm – 1 light-decade

==100 petametres==
[[File:1e17m comparison 100 light years nebula clusters.png|thumb|Lengths with order of magnitude 1e17m: yellow Vernal Point arrow traces hundred light-year radius circle with smaller ten light-year circle at right; globular cluster Messier 5 in background; 12 light-year radius Orion Nebula middle right; 50-light-year-wide view of the Carina Nebula bottom left; Pleiades cluster and Bubble nebula with similar diametres each around 10 light-years bottom right; grey arrows show distances from Sun to stars Aldebaran (65 light-years) and Vega (25 light-years)]]

To help compare different [[distance]]s this section lists lengths between 10<sup>17</sup> [[metre|m]] (100 [[#1 petametre|Pm]] or 11 [[light-year]]s) and 10<sup>18</sup> m (106 light-years).
*110 Pm – 12 light-years – Distance to [[Tau Ceti]]
*230 Pm – 24 light-years – Diametre of the [[Orion Nebula]]<ref name=apj667>{{cite journal|last=Sandstrom|first=Karin M|author2=Peek, J. E. G.|author3=Bower, Geoffrey C.|author4=Bolatto, Alberto D.|author5=Plambeck, Richard L.|title=A Parallactic Distance of {{val|389|+24|-21}} parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations|journal=The Astrophysical Journal|year=1999|volume=667|issue=2|pages=1161–1169|doi=10.1086/520922|bibcode=2007ApJ...667.1161S|arxiv=0706.2361|s2cid=18192326}}</ref><ref>diametre=sin(65 arcminutes)*1270 light-years=24; where "65.00 × 60.0 (arcmin)" sourced from [https://web.archive.org/web/20120318092511/http://spider.seds.org/ngc/revngcic.cgi?NGC1976 Revised NGC Data for NGC 1976]{{cbignore}}</ref>
*240 Pm – 25 light-years – Distance to [[Vega]]
*260 Pm – 27 light-years – Distance to [[Beta Canum Venaticorum|Chara]], a star approximately as bright as the Sun. Its faintness gives an idea how the [[Sun]] would appear when viewed from this distance.
*308.568 Tm – 32.6 light-years – 1 dekaparsec
*350 Pm – 37 light-years – distance to [[Arcturus]]
*373.1 Pm – 39.44 light-years – distance to [[TRAPPIST-1]], a star recently discovered to have 7 planets around it 
*400 Pm – 42 light-years – distance to [[Capella (star)|Capella]]
*620 Pm – 65 light-years – distance to [[Aldebaran]]
*750 Pm – 79.36 light-years – distance to [[Regulus]]
*900 Pm – 92.73 light-years – distance to [[Algol]]
*946 Pm – 1 light-century

==1 exametre==
[[File:1e18m comparison 1000 light years nebula clusters.png|thumb|Lengths with order of magnitude 1e18m: thousand light-year radius circle with yellow arrow and 100 light-year circle at right with globular cluster Messier 5 within and Carina Nebula in front; globular cluster Omega Centauri to left of both; part of the 1,400-light-year-wide Tarantula Nebula fills the background]]

The ''{{vanchor|exametre}}'' ([[SI]] symbol: ''{{vanchor|Em}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10<sup>18</sup> [[metre|metre]]s. To help compare different [[distance]]s this section lists lengths between 10<sup>18</sup>&nbsp;[[metre|m]] (1&nbsp;[[exametre|Em]] or 105.7 [[light-year]]s) and 10<sup>19</sup>&nbsp;m (10&nbsp;Em or 1,057 light-years).

*1.2 Em – 129 light-years – diametre of [[Messier 13]] (a typical [[globular cluster]])
*1.6 Em – 172 ± 12.5 light-years – diametre of [[Omega Centauri]] (one of the largest-known [[globular cluster]]s, perhaps containing over a million [[star]]s)<ref>distance &times; sin( diametre_angle ), using distance of 5kpc (15.8 ± 1.1 kly) and angle 36.3', = 172 ± 12.5 ly.<!-- ±12,5 ly is derived from min to max distances from G. van de Ven 2006 paper: 4.5 to 5.2kpc --></ref><ref name="vandeVenetal2006">{{cite journal|last1=van de Ven|first1=G.|author2=van den Bosch, R. C. E.|author3=Verolme, E. K.|author4=de Zeeuw, P. T.|title=The dynamical distance and intrinsic structure of the globular cluster ω Centauri|journal=[[Astronomy and Astrophysics]]|year=2006|volume=445|issue=2|pages=513–543|bibcode=2006A&A...445..513V|doi=10.1051/0004-6361:20053061|quote=best-fit dynamical distance D=4.8±0.3 kpc ... consistent with the canonical value 5.0±0.2 kpc obtained by photometric methods|arxiv=astro-ph/0509228|s2cid=15538249}}</ref><!-- 15.8 ±1.1 kly is from min to max distances from 2006 paper: 4.5 to 5.2kpc --><!-- note 2006 paper states dynamical bestfit is 4.8 ± 0.3 pc, canonical value from photometric methods is 5.0 ± 0.2; while hubblesite simplifies to 17000 ly -->
*3.08568 Em – 326.1 light-years – 1 hectoparsec
*3.1 Em – 310 light-years – distance to [[Canopus (star)|Canopus]] according to ''[[Hipparcos]]''<ref name="van Leeuwen2007">{{cite journal|title=Validation of the new Hipparcos reduction|last1=van Leeuwen|first1=F.|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|year=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357|s2cid=18759600}} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-ref=VIZ53e6b48255b3&-out.add=.&-source=I/311/hip2&recno=30362 Vizier catalog entry]</ref>
*3.9 Em – 410 light-years – distance to [[Betelgeuse]] according to ''Hipparcos''<ref>{{Cite journal |last1=Neuhäuser |first1=R |last2=Torres |first2=G |last3=Mugrauer |first3=M |last4=Neuhäuser |first4=D L |last5=Chapman |first5=J |last6=Luge |first6=D |last7=Cosci |first7=M |date=2022-07-29 |title=Colour evolution of Betelgeuse and Antares over two millennia, derived from historical records, as a new constraint on mass and age |journal=Monthly Notices of the Royal Astronomical Society |volume=516 |issue=1 |pages=693–719 |doi=10.1093/mnras/stac1969 |doi-access=free |issn=0035-8711|arxiv=2207.04702 }}</ref>
*6.2 Em – 650 light-years – distance to the [[Helix Nebula]], located in the constellation [[Aquarius (constellation)|Aquarius]]<ref name="Harrisetal2007">{{cite journal|bibcode=2007AJ....133..631H|title=Trigonometric Parallaxes of Central Stars of Planetary Nebulae|year=2007|journal=The Astronomical Journal|volume=133|issue=2|pages=631–638|doi=10.1086/510348|author=Harris, Hugh C.|display-authors=4|author2=Dahn, Conard C.|author3=Canzian, Blaise|author4=Guetter, Harry H.|author5=Leggett, S. K.|author6=Levine, Stephen E.|author7=Luginbuhl, Christian B.|author8=Monet, Alice K. B.|author9=Monet, David G.|author10=Pier, Jeffrey R.|author11=Stone, Ronald C.|author12=Tilleman, Trudy|author13=Vrba, Frederick J.|author14=Walker, Richard L.|arxiv=astro-ph/0611543|s2cid=18261027}}</ref>
*8.2 Em – 860 light-years – distance to [[Rigel]] according to ''Hipparcos''<ref name="van Leeuwen2007"/>
*9.4 Em — 1 light-millennium – 1000 light-years

==10 exametres==

To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 10 [[exametre|Em]] (10<sup>19</sup> [[metre|m]] or 1,100 [[light-year]]s).

*10.6 Em – 1,120 light-years – distance to [[WASP-96b]]
*13 Em – 1,300 light-years – distance to the [[Orion Nebula]]<ref>
{{cite journal|last1=Reid|first1=M. J.|first2=K. M.|last2=Menten|first3=X. W.|last3=Zheng|first4=A.|last4=Brunthaler|first5=L.|last5=Moscadelli|first6=Y.|last6=Xu|first7=B.|last7=Zhang|first8=M.|last8=Sato|first9=M.|last9=Honma|first10=T.|last10=Hirota|first11=K.|last11=Hachisuka|first12=Y. K.|last12=Choi|first13=G. A.|last13=Moellenbrock|first14=A.|last14=Bartkiewicz|display-authors=1|year=2009|title=Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parametres and Non-Circular Motions|journal=[[Astrophysical Journal]]|volume=700|issue=1|pages=137–148|arxiv=0902.3913|doi=10.1088/0004-637X/700/1/137|bibcode=2009ApJ...700..137R|s2cid=11347166}}</ref>
*14 Em – 1,500 light-years – approximate thickness of the [[Galactic plane|plane]] of the [[Milky Way]] [[galaxy]] at the [[Sun]]'s location
*14.2 Em – 1,520 light-years – diametre of the [[NGC 604]]
*30.8568 Em – 3,261.6 light-years – 1 [[parsec|kiloparsec]]
*31 Em – 3,200 light-years – distance to [[Deneb]] according to ''[[Hipparcos]]''
*46 Em – 4,900 light-years – distance to [[OGLE-TR-56]], the first [[extrasolar planet]] discovered using the [[extrasolar planet#Transit method|transit method]]
*47 Em – 5,000 light-years – distance to the [[Boomerang nebula]], coldest place known ([[1 E0 K|1 K]])
*53 Em – 5,600 light-years – distance to the [[globular cluster]] [[Messier 4|M4]] and the [[extrasolar planet]] [[PSR B1620-26 b]] within it
*61 Em – 6,500 light-years – distance to [[Perseus Spiral Arm]] (next spiral arm out in the Milky Way galaxy)
*71 Em – 7,500 light-years – distance to [[Eta Carinae]]
*94.6073 Em – 1 light-decamillennium = 10,000 light-years

==100 exametres==
To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 100 [[exametre|Em]] (10<sup>20</sup> [[metre|m]] or 11,000 [[light-year]]s).

*150 Em – 16,000 light-years – diametre of the [[Small Magellanic Cloud]], a [[dwarf galaxy]] orbiting the [[Milky Way]]
*200 Em – 21,500 light-years – distance to [[OGLE-2005-BLG-390Lb]]
*240 Em – 25,000 light-years – distance to the [[Canis Major Dwarf Galaxy]]
*260 Em – 28,000 light-years – distance to the center of the [[Milky Way|Galaxy]]
*400 Em – 48,000 light years – diametre of the [[Fireworks Galaxy]]
*830 Em – 88,000 light-years – distance to the [[Sagittarius Dwarf Elliptical Galaxy]]
*946 Em – 1 light-centum-millennium = 100,000 light-years

==1 zettametre==

The ''{{vanchor|zettametre}}'' ([[SI]] symbol: ''{{vanchor|Zm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10<sup>21</sup> [[metre|metre]]s.<ref name="bipm.org">{{cite web|title=SI Brochure: The International System of Units (SI)|url=https://www.bipm.org/en/publications/si-brochure/|website=International Committee for Weights and Measures|publisher=Organisation Intergouvernementale de la Convention du Mètre|access-date=11 October 2014}}</ref> 
To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 1&nbsp;[[zettametre|Zm]] (10<sup>21</sup>&nbsp;[[metre|m]] or 110,000 [[light-year]]s).

*1.7 Zm – 179,000 light-years – distance to the [[Large Magellanic Cloud]], largest [[satellite galaxy]] of the [[Milky Way]]
*<1.9 Zm – <200,000 light-years – revised estimated diametre of the disc of the [[Milky Way|Milky Way Galaxy]]. The size was previously thought to be half of this.
*2.0 Zm – 210,000 light-years – distance to the [[Small Magellanic Cloud]]
*2.8 Zm – 300,000 light-years – distance to the [[Intergalactic Wanderer]], one of the most distant [[globular cluster]]s of Milky Way
*8.5 Zm – 900,000 light-years – distance to the [[Leo I Dwarf Galaxy]], farthest-known [[Milky Way]] satellite [[galaxy]]
*9.5 Zm – 1 light-megaannum = 1,000,000 light-years

==10 zettametres==
To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 10 [[zettametre|Zm]] (10<sup>22</sup> [[metre|m]] or 1.1 million [[light-year]]s).

*24 Zm – 2.5 million light-years – distance to the [[Andromeda Galaxy]], the nearest major [[galaxy]].
*30.8568 Zm – 3.2616 million light-years – 1 [[parsec|megaparsec]]
*40 Zm – 4.2 million light-years – distance to the [[IC 10]], a distant member of the [[Local Group]] of [[galaxy|galaxies]]
*49.2 Zm – 5.2 million light-years – width of the [[Local Group]] of [[galaxy|galaxies]]
*95 Zm – 10 million light-years – distance to the [[Sculptor Galaxy]] in the [[Sculptor Group]] of galaxies
*95 Zm – 10 million light-years – distance to the [[Maffei 1]], the nearest giant [[elliptical galaxy]] in the [[Maffei 1 group of galaxies|Maffei 1 Group]]

==100 zettametres==
To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 100 [[zettametre|Zm]] (10<sup>23</sup> [[metre|m]] or 11 million [[light-year]]s).

*140 Zm – 15 million light-years – distance to [[Centaurus A]] galaxy
*250 Zm – 27 million light-years – distance to the [[Pinwheel Galaxy]]
*280 Zm – 30 million light-years – distance to the [[Sombrero Galaxy]]
*570 Zm – 60 million light-years – approximate distance to the [[Virgo cluster]], nearest [[galaxy cluster]]
*620 Zm – 65 million light-years – approximate distance to the [[Fornax cluster]]
*800 Zm – 85 million light-years – approximate distance to the [[Eridanus cluster]]

==1 yottametre==
The ''{{vanchor|yottametre}}'' ([[SI]] symbol: ''{{vanchor|Ym}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10<sup>24</sup>&nbsp;[[metre|metre]]s.<ref name="bipm.org"/>

To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 1 Ym (10<sup>24</sup> [[metre|m]] or 105.702 million [[light-year]]s).
*1.2 Ym – 127 million light-years – distance to the closest observed [[gamma ray burst]] [[GRB 980425]]
*1.3 Ym – 137 million light-years – distance to the [[Centaurus Cluster]] of [[galaxies]], the nearest large [[supercluster]]
*1.9 Ym – 201 million light-years – diametre of the [[Local Supercluster]]
*2.17 Ym – 1 light-galactic-years – 230 million light-years
*2.3 Ym – 225 to 250 million light-years – distance light travels in vacuum in one [[galactic year]]
*2.8 Ym – 296 million light-years – distance to the [[Coma Cluster]]
*3.15 Ym – 330 million light years – diametre of the [[Boötes Void]]
*3.2 Ym – 338 million light-years – distance to [[Stephan's Quintet]]
*4.7 Ym – 496 million light-years – length of the [[Great Wall (astronomy)|CfA2 Great Wall]], one of the largest observed superstructures in the [[Universe]]
*6.1 Ym – 645 million light-years – distance to the [[Shapley Supercluster]]
*9.5 Ym – 996 million light-years – diametre of the [[Eridanus Supervoid]]

==10 yottametres==
[[File:Superclusters atlasoftheuniverse.gif|thumb|The universe within one billion light-years of Earth]]

To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 10 [[yottametre|Ym]] (10<sup>25</sup> [[metre|m]] or 1.1 billion [[light-year]]s). At this scale, expansion of the [[universe]] becomes significant. Distance of these objects are derived from their measured [[redshift]]s, which depends on the [[physical cosmology|cosmological]] models used.

*13 Ym – 1.37 billion light-years – length of the [[South Pole Wall]]
*13 Ym – 1.38 billion light-years – length of the [[Sloan Great Wall]]
*18 Ym – redshift 0.16 – 1.9 billion light-years – distance to the [[quasar]] [[3C 273]] ([[distance measures (cosmology)#Types of distance measures|light travel distance]])
*30.8568 Ym – 3.2616 billion light-years – 1 gigaparsec
*31.2204106 Ym − 3.3 billion light-years − length of [[The Giant Arc]], a large cosmic structure discovered in 2021
*33 Ym – 3.5 billion light-years – maximum distance of the [[2dF Galaxy Redshift Survey]] (light travel distance)
*37.8 Ym – 4 billion light-years – length of the [[Huge-LQG]]
*75 Ym – redshift 0.95 – 8 billion light-years – approximate distance to the [[supernova]] SN 2002dd in the [[Hubble Deep Field North]] (light travel distance)
*85 Ym – redshift 1.6 – 9 billion light-years – approximate distance to the [[gamma-ray burst]] [[GRB 990123]] (light travel distance)
*94.6 Ym – 10 billion light-years – approximate distance to quasar OQ172
*94.6 Ym – 10 billion light-years – length of the [[Hercules–Corona Borealis Great Wall]], one of the [[list of largest cosmic structures|largest and most massive-known cosmic structures known]]

==100 yottametres==
To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 100 [[yottametre|Ym]] (10<sup>26</sup> [[metre|m]] or 11 billion [[light-year]]s). At this scale, expansion of the [[universe]] becomes significant. Distance of these objects are derived from their measured [[redshift]]s, which depend on the [[physical cosmology|cosmological]] models used.

*124 Ym – redshift 7.54 – 13.1 billion light-years – [[Distance measures (cosmology)#Types of distance measures|light travel distance]] (LTD) to the [[quasar]] [[ULAS J1342+0928]], the [[List of quasars#Most distant quasars|most distant-known quasar]] as of 2017
*130 Ym – redshift 1,000 – 13.8 billion light-years – distance (LTD) to the source of the [[Cosmic microwave background|cosmic microwave background radiation]]; radius of the observable [[universe]] measured as a LTD
*260 Ym – 27.4 billion light-years – diametre of the observable universe (double LTD)
*440 Ym – 46 billion light-years – radius of the universe measured as a [[comoving distance]]
*590 Ym – 62 billion light-years – cosmological [[event horizon]]: the largest comoving distance from which light will ever reach us (the observer) at any time in the future
*886.48 Ym – 93.7 billion light-years – the diametre of the [[observable universe]] (twice the [[particle horizon]]); however, there might be unobserved distances that are even greater.

==1 ronnametre==
The ''{{vanchor|ronnametre}}'' ([[SI]] symbol: ''{{vanchor|Rm}}'') is a [[Units of measurement|unit]] of [[length]] in the [[metric system]] equal to 10<sup>27</sup>&nbsp;[[metre|metre]]s.<ref name="bipm.org"/>

To help compare different [[orders of magnitude]], this section lists [[distance]]s starting at 1 Rm (10<sup>27</sup> [[metre|m]] or 105.7 billion [[light-year]]s). At this scale, expansion of the [[universe]] becomes significant. Distance of these objects are derived from their measured [[redshift]]s, which depend on the [[physical cosmology|cosmological]] models used.
*>1 Rm – >105.7 billion light-years – size of universe beyond the [[observable universe|cosmic light horizon]], depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be [[infinity#Cosmology|infinite]] (see [[Shape of the universe]]) as previously mentioned.
*2.764 Rm - 292.2 billion light-years – circumference of the observable universe, as it is in the shape of a sphere.
*≈10<sup>10<sup>10<sup>122</sup></sup></sup>[[light-year]]s – the possible size of the universe after [[cosmological inflation]].
*≈∞ light-years – theoretical size of the [[multiverse]] if it exists.

==See also==
*[[Fermi problem]]
*[[Scale (analytical tool)]]
*[[Spatial scale]]
*[[The Scale of the Universe]]

==Notes==
{{Reflist|group=note}}

==References==
{{Reflist}}

==External links==
* [http://www.vendian.org/howbig/ How Big Are Things?] – displays orders of magnitude in successively larger rooms.
* [https://web.archive.org/web/20120702055359/http://microcosm.web.cern.ch/microcosm/P10/english/welcome.html Powers of Ten] – Travel across the Universe.<!---Altering perspective by changing scale by just a few powers of ten (interactive) {{dead link|date=May 2013}}--->
* [https://web.archive.org/web/20080412094332/http://www.shekpvar.net/~dna/Publications/Cosmos/cosmos.html Cosmos – <!---Illustrated Dimensional---> Journey from microcosmos to macrocosmos] (Digital Nature Agency).
* [http://htwins.net/scale2/ Scale of the universe] – interactive guide to length magnitudes
* {{youTube|FglEbPXxka4|Video (4:29)}} – [https://venturebeat.com/2020/03/16/orders-of-magnitude-vr-reveals-humanitys-tiny-scale-in-the-universe/ Orders of Magnitude] (March 2020).

{{Metric units of length}}
{{Orders of magnitude}}
{{Units of length used in Astronomy}}
{{Portal bar|Physics|Mathematics|Astronomy|Stars|Spaceflight|Outer space|Solar System|Science}}

[[Category:Orders of magnitude (length)| ]]
[[Category:Length]]
[[Category:Orders of magnitude|Length]]
[[Category:Lists by length]]