Editing Paper size (section)

== International standard paper sizes==
{{Main|ISO 216}}
{{Hatnote|See [[Switching barriers|Switching costs]], [[Network effect]]s and [[Standardization]] for possible reasons for differing regional adoption rates of the [[International Organization for Standardization|ISO]] standard sizes.}}
[[File:Prevalent default paper size.svg|thumb|Map of the world showing adoption of paper sizes, according to the [[Common Locale Data Repository]] in 2017
{{legend|#0000BB|ISO A4 exclusively}}
{{legend|#4444BB|ISO A4 primarily}}
{{legend|#FF8888|US-Letter primarily}}
{{legend|#FF0000|US-Letter predominantly}}
{{legend|#BB0000|US-Letter exclusively}}
]]

The international paper size standard is [[ISO 216]]. It is based on the German [[Deutsches Institut für Normung|DIN]] 476 standard for paper sizes. Each ISO paper size is one half of the area of the next larger size in the same series. ISO paper sizes are all based on a single [[aspect ratio (image)|aspect ratio]] of the [[square root of 2]], or approximately 1:1.41421. There are different series, as well as several extensions.

The following international paper sizes are included in [[Cascading Style Sheets]] (CSS): ''A3'', ''A4'', ''A5'', ''B4'', ''B5''.<ref name="mozilla.org">{{cite web |url=https://developer.mozilla.org/en-US/docs/Web/CSS/@page/size|title=size |access-date=25 January 2017 |archive-url=https://web.archive.org/web/20170202023142/https://developer.mozilla.org/en-US/docs/Web/CSS/@page/size|archive-date=2 February 2017 |url-status=live}}</ref>

===A series<span class="anchor" id="ISO A"></span><span class="anchor" id="DIN A"></span><span class="anchor" id="SIS A"></span><span class="anchor" id="JIS A"></span>===
[[File:A size illustration2.svg|thumb|right|A size chart illustrating the ISO A series]]

There are 11 sizes in the A series, designated A0–A10, all of which have an aspect ratio of <math>\frac{a}{b} = \sqrt{2} \approx 1.41421\ldots</math>, where ''a'' is the long side and ''b'' is the short side.

Since A series sizes share the same aspect ratio <math>(\sqrt{2}),</math> they can be scaled to other A series sizes without being distorted, and two sheets can be reduced to fit on exactly one sheet without any cutoff or margins.

The A0 base size is defined as having an area of 1&nbsp;m{{sup|2}}; given an aspect ratio of <math>\sqrt{2}</math>, the dimensions of A0 are:

<math>\sqrt[4]2\,\mathrm{m}</math> by <math>\frac1\sqrt[4]2\,\mathrm{m}</math>.

or, rounded to the nearest millimetre, {{cvt|1189|x|841|mm|inch}}.

A series sizes are related in that the smaller dimension of a given size is the larger dimension of the next smaller size, and folding an A series sheet in half in its larger dimension—that is, folding it in half parallel to its short edge—results in two halves that are each the size of the next smaller A series size. As such, a folded brochure of a given A-series size can be made by folding sheets of the next larger size in half, e.g. A4 sheets can be folded to make an A5 brochure. The fact that halving a sheet with an aspect ratio of <math>\sqrt{2}</math> results in two sheets that themselves both have an aspect ratio of <math>\sqrt{2}</math> is proven as follows:

<math>\frac{a}{b} = \sqrt{2},</math>

where ''a'' is the long side and ''b'' is the short side. The aspect ratio for the new dimensions of the folded paper is:

<math>\frac{b}{\frac{a}{2}} = 2\frac{b}{a} = 2\frac{1}{\sqrt{2}} = \sqrt{2} = \frac{a}{b}.</math>

The advantages of basing a paper size upon an aspect ratio of <math>\sqrt{2}</math> were noted in 1786 by the German scientist and philosopher [[Georg Christoph Lichtenberg]].<ref>{{cite web |url=http://www.cl.cam.ac.uk/~mgk25/lichtenberg-letter.html |title=Lichtenberg's letter to Johann Beckmann |publisher=Markus Kuhn |date=7 February 2006 |access-date=3 April 2023 |archive-url=https://web.archive.org/web/20111231214454/http://www.cl.cam.ac.uk/~mgk25/lichtenberg-letter.html |archive-date=31 December 2011 |url-status=live}}</ref> He also observed that some raw sizes already adhered to that ratio so that when a sheet is folded, the length to width ratio does not change.

Briefly after the introduction of the [[metric system]], a handful of new paper formats equivalent to modern ones were developed in France, having been proposed by the mathematician [[Lazare Carnot]], and published for judicial purposes in 1798 during the [[French Revolution]]:<ref name="B237">{{cite journal |title=Loi sur le timbre (Nº 2136) |trans-title=Stamp Act (No. 2136) |date=3 November 1798 |journal=Bulletin des Lois de la République |issue=237 |pages=1–2 |language=fr |publisher=Republic of France |location=Paris |url=http://www.cl.cam.ac.uk/~mgk25/loi-timbre.html |url-status=live |access-date=2024-01-20 |archive-url=https://web.archive.org/web/20090426170239/http://www.cl.cam.ac.uk/~mgk25/loi-timbre.html |archive-date=26 April 2009 |via=Markus Kuhn }}</ref>

* {{lang|fr|Grand registre}} (A2)
* {{lang|fr|Moyen papier}} (A3)
* {{lang|fr|Grand papier}} (B3)
* {{lang|fr|Petit papier}} (B4)
* {{lang|fr|Demi feuille}} (B5)
* {{lang|fr|Effets de commerce}} (B6)

These were never widely adopted, however.

Early in the 20th century, the ratio was used to specify the [[#Weltformat|''world format'']] starting with {{cvt|1|cm}} as the short edge of the smallest size. Walter Porstmann started with the largest sizes instead, assigning one an area of {{cvt|1|m2}} (A0) and the other a short edge of {{cvt|1|m}} (B0). He thereby turned the forgotten French sizes (relatively few in number) into a logically-simple and comprehensive plan for a full range of paper sizes, while introducing systematic alphanumeric monikers for them. Generalized to nothing less than four series, this system was introduced as a [[#German original|DIN standard (DIN 476)]] in Germany in 1922, replacing a vast variety of other paper formats. Even today, the paper sizes are called "DIN A4" ({{IPA|de|diːn.ʔaː.fiːɐ̯|IPA}}) in everyday use in Germany and Austria.

The DIN 476 standard spread quickly to other countries. Before the outbreak of [[World War II]], it had been adopted by the following countries in Europe:

{{div col|colwidth=22em}}
* [[Belgium]] (1924)
* [[Netherlands]] (1925)
* [[Norway]] (1926)
* [[Finland]] (1927)
* [[Switzerland]] (1929)
* Sweden (1930) with [[#Swedish extension|later extensions]]
* [[Soviet Union]] (1934) with [[#Soviet variants|custom extensions]]
* [[Hungary]] (1938)
* Italy (1939)
{{div col end}}

During World War II, the standard spread to South America and was adopted by [[Uruguay]] (1942), [[Argentina]] (1943) and Brazil (1943), and afterwards spread to other countries:

{{div col|colwidth=22em}}
* [[Australia]] (1974)
* [[Austria]] (1948)
* [[Bangladesh]] (1972)
* [[Barbados]] (1973)
* [[Chile]] (1968)
* [[Colombia]] (1975)
* [[Czechoslovakia]] (1953)
* [[Denmark]] (1953)
* [[Ecuador]] (1974)
* [[France]] (1967)
* [[Greece]] (1970)
* [[Iceland]] (1964)
* [[India]] (1957) with [[#Indian variants|custom extensions]]
* [[Iran]] (1948)
* [[Ireland]] (1959)
* [[Israel]] (1954)
* [[Japan]] (1951) with [[#Japanese variation|different B series]]
* [[Kuwait]] (1975)
* [[Mexico]] (1965)
* [[New Zealand]] (1963)
* [[Peru]] (1967)
* [[Poland]] (1957)
* [[Portugal]] (1954)
* [[Rhodesia]] (1970)
* [[Romania]] (1949)
* [[Singapore]] (1970)
* [[South Africa]] (1966)
* [[Spain]] (1947)
* [[Thailand]] (1973)
* [[Turkey]] (1967)
* [[United Kingdom]] (1971)<ref>{{cite web|author=Metrication Board|title=Final report of the Metrication Board|date=1980|publisher=Department of Trade and Industry Consumer and Competition Policy Directorate|page=17|url=http://ukma.org.uk/sites/default/files/met1980.pdf|archive-url=https://web.archive.org/web/20130501034405/http://ukma.org.uk/sites/default/files/met1980.pdf|access-date=29 September 2021|archive-date=1 May 2013}}</ref>
* [[Venezuela]] (1962)
* [[SFRY|Yugoslavia]](1956)
{{div col end}}

By 1975, so many countries were using the German system that it was established as an [[International Organization for Standardization|ISO]] standard, as well as the official United Nations document format. By 1977, A4 was the standard letter format in 88 of 148 countries. Today the standard has been adopted by all countries in the world except the United States and Canada. In Mexico, [[Costa Rica]], [[Colombia]], [[Venezuela]], Chile, and the [[Philippines]], the [[Letter (paper size)|US letter]] format is still in common use, despite their official adoption of the ISO standard.

The weight of an A-series sheet of a given [[Paper density#Basis weight|paper weight]] can be calculated by knowing the ratio of its size to the A0 sheet. For example, an A4 sheet is {{frac|16}} the size of an A0 sheet, so if it is made from {{nowrap|80 g/m{{sup|2}}}} paper, it weighs {{frac|16}} of {{cvt|80|g}}, which is {{cvt|5|g}}.

===B series<span class="anchor" id="ISO B"></span><span class="anchor" id="DIN B"></span><span class="anchor" id="SIS B"></span>===
[[File:B size illustration2.svg|thumb|right|A size chart illustrating the ISO B series]]

The B series paper sizes are less common than the A series. They have the same aspect ratio as the A series:

<math>\frac{a}{b}=\sqrt{2} = 1.41421...</math>

However, they have a different area. The area of B series sheets is in fact the [[geometric mean]] of successive A series sheets. B1 is between A0 and A1 in size, with an area of <math>\frac{1}{\sqrt{2}}</math> m{{sup|2}}, or about {{cvt|0.707|m2}}. As a result, B0 is 1 metre wide, and other sizes of the series are a half, a quarter, or further fractions of a metre wide: in general, every B size has exactly one side of length <math>\frac{1 \operatorname{m}}{2^n}</math> for <math>n \in \mathbb{N}</math>. That side is the short side for B0, B2, B4, etc., and the long side for B1, B3, B5, etc.

While less common in office use, the B series is used for a variety of applications in which one A-series size would be too small but the next A-series size is too large, or because they are convenient for a particular purpose.

* B4, B5, and B6 are used for [[envelope]]s that will hold C-series envelopes.
* B4 is quite common in printed music sheets.
* B5 is a relatively common choice for books.
* B7 is equal to the passport size ID-3 from [[ISO/IEC 7810]].
* Many posters use B-series paper or a close approximation, such as 50&nbsp;cm × 70&nbsp;cm ~ B2.

<!--someone please confirm the validity of the following sentences:-->
The B-series is widely used in the printing industry to describe both paper sizes and [[printing press]] sizes, including [[digital printing|digital presses]]. B3 paper is used to print two US letter or A4 pages side by side using [[imposition]]; four pages would be printed on B2, eight on B1, etc.{{qn|date=January 2020}}

===C series<span class="anchor" id="ISO C"></span><span class="anchor" id="DIN C"></span><span class="anchor" id="SIS C"></span>===
[[File:C size illustration2.svg|thumb|right|A size chart illustrating the ISO C series]]
The C series is defined in [[ISO 269]], which was withdrawn in 2009 without a replacement, but is still specified in several national standards. It is primarily used for envelopes. The area of C series sheets is the geometric mean of the areas of the [[#ISO A|A]] and [[#ISO B|B series]] sheets of the same number; for instance, the area of a C4 sheet is the geometric mean of the areas of an A4 sheet and a B4 sheet. This means that C4 is slightly larger than A4, and slightly smaller than B4. The practical usage of this is that a letter written on A4 paper fits inside a C4 envelope, and both A4 paper and C4 envelopes fit inside a B4 envelope.

Some envelope formats with mixed sides from adjacent sizes (and thus an approximate aspect ratio of 2:1) are also defined in national adaptations of the ISO standard, e.g. DIN C6/C5 (also known as C65) is 114&nbsp;mm × 229&nbsp;mm where the common side to C5 and C6 is 162&nbsp;mm. This format allows an envelope holding an A-sized paper folded in three, e.g. for the C65, an A4.

=== Overview of ISO paper sizes ===
{| class="wikitable" style="text-align: center;"
|+ ISO paper sizes in portrait view (with rounded inch values)
! Format
!colspan="3"| [[#ISO A|A series]]<ref>{{cite web |url=http://www.papersizes.org/a-paper-sizes.htm |title=A Paper Sizes - A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 |access-date=25 January 2017 |archive-url=https://web.archive.org/web/20161029141208/http://www.papersizes.org/a-paper-sizes.htm |archive-date=29 October 2016 |url-status=live}}</ref>
!colspan="3"| [[#ISO B|B series]]<ref>{{cite web |url=http://www.papersizes.org/b-paper-sizes.htm |title=B Paper Sizes - B0, B1, B2, B3, B4, B5, B6, B7, B8, B9, B10 |access-date=25 January 2017 |archive-url=https://web.archive.org/web/20161204151334/http://www.papersizes.org/b-paper-sizes.htm |archive-date=4 December 2016 |url-status=live}}</ref>
!colspan="3"| [[#ISO C|C series]]<ref>{{cite web |url=http://www.papersizes.org/c-envelope-sizes.htm |title=Envelope Sizes - ISO C Series & DL Envelopes |access-date=25 January 2017 |archive-url=https://web.archive.org/web/20161204141443/http://www.papersizes.org/c-envelope-sizes.htm |archive-date=4 December 2016 |url-status=live}}</ref>
|-
! rowspan="2" | Size
!colspan="2" | short × long || Notional area
!colspan="2" | short × long || Notional area
!colspan="2" | short × long || Notional area
|-
! mm || in || m{{sup|2}}
! mm || in || m{{sup|2}}
! mm || in || m{{sup|2}}
|-
! 0
|  841 × 1189 || {{nowrap|{{convert|841 x 1189|mm|1|abbr=values|disp=out}}}} {{anchor|A0}} || 2{{sup|0}} = 1 <!-- anchors in tables don't need to be subst'd -->
| 1000 × 1414 || {{nowrap|{{convert|1000 x 1414|mm|1|abbr=values|disp=out}}}} {{anchor|B0}} || 2{{sup|{{frac|1|2}}}} ≈ {{round|1.4142135624|3}}
|  917 × 1297 || {{nowrap|{{convert|917 x 1297|mm|1|abbr=values|disp=out}}}} {{anchor|C0}} || 2{{sup|{{frac|1|4}}}} ≈ {{round|1.189207115|3}}
|-
! 1 
|   594 × 841 || {{nowrap|{{convert|594 x 841|mm|1|abbr=values|disp=out}}}} {{anchor|A1}} || 1/2 = 0.5
|  707 × 1000 || {{nowrap|{{convert|707 x 1000|mm|1|abbr=values|disp=out}}}} {{anchor|B1}} || 2{{sup|−{{frac|1|2}}}} ≈ {{round|0.7071067812|3}}
|   648 × 917 || {{nowrap|{{convert|648 x 917|mm|1|abbr=values|disp=out}}}} {{anchor|C1}} || 2{{sup|−{{frac|3|4}}}} ≈ {{round|0.5946035575|3}}
|-
! 2 
|   420 × 594&nbsp;|| {{nowrap|{{convert|420 x 594|mm|1|abbr=values|disp=out}}}} {{anchor|A2}} || 1/2{{sup|2}} = 0.25
|   500 × 707 || {{nowrap|{{convert|500 x 707|mm|1|abbr=values|disp=out}}}} {{anchor|B2}} || 2{{sup|−{{frac|1|1|2}}}} ≈ {{round|0.3535533906|3}}
|   458 × 648 || {{nowrap|{{convert|458 x 648|mm|1|abbr=values|disp=out}}}} {{anchor|C2}} || 2{{sup|−{{frac|1|3|4}}}} ≈ {{round|0.2973017788|3}}
|-
! 3
|   297 × 420 || {{nowrap|{{convert|297 x 420|mm|1|abbr=values|disp=out}}}} {{anchor|A3}} || 1/2{{sup|3}} = 0.125
|   353 × 500 || {{nowrap|{{convert|353 x 500|mm|1|abbr=values|disp=out}}}} {{anchor|B3}} || 2{{sup|−{{frac|2|1|2}}}} ≈  {{round|0.1767766953|3}}
|   324 × 458 || {{nowrap|{{convert|324 x 458|mm|1|abbr=values|disp=out}}}} {{anchor|C3}} || 2{{sup|−{{frac|2|3|4}}}} ≈  {{round|0.1486508894|3}}
|-
! 4
|   210 × 297 || {{nowrap|{{convert|210 x 297|mm|1|abbr=values|disp=out}}}} {{anchor|A4}} || 1/2{{sup|4}} = 0.0625
|   250 × 353 || {{nowrap|{{convert|250 x 353|mm|1|abbr=values|disp=out}}}} {{anchor|B4}} || 2{{sup|−{{frac|3|1|2}}}} ≈  {{round|0.0883883476|3}}
|   229 × 324 || {{nowrap|{{convert|229 x 324|mm|1|abbr=values|disp=out}}}} {{anchor|C4}} || 2{{sup|−{{frac|3|3|4}}}} ≈  {{round|0.0743254447|4}}
|-
! 5
|   148 × 210 || {{nowrap|{{convert|148 x 210|mm|1|abbr=values|disp=out}}}} {{anchor|A5}} || 1/2{{sup|5}} ≈ {{round|0.03125|4}}
|   176 × 250 || {{nowrap|{{convert|176 x 250|mm|1|abbr=values|disp=out}}}} {{anchor|B5}} || 2{{sup|−{{frac|4|1|2}}}} ≈  {{round|0.0441941738|3}}
|   162 × 229 || {{nowrap|{{convert|162 x 229|mm|1|abbr=values|disp=out}}}} {{anchor|C5}} || 2{{sup|−{{frac|4|3|4}}}} ≈  {{round|0.0371627223|4}}
|-
! 6
|   105 × 148 || {{nowrap|{{convert|105 x 148|mm|1|abbr=values|disp=out}}}} {{anchor|A6}} || 1/2{{sup|6}} ≈ {{round|0.015625|4}}
|   125 × 176 || {{nowrap|{{convert|125 x 176|mm|1|abbr=values|disp=out}}}} {{anchor|B6}} || 2{{sup|−{{frac|5|1|2}}}} ≈  {{round|0.0220970869|4}}
|   114 × 162 || {{nowrap|{{convert|114 x 162|mm|1|abbr=values|disp=out}}}} {{anchor|C6}} || 2{{sup|−{{frac|5|3|4}}}} ≈  {{round|0.0185813612|4}}
|-
! 7
|    74 × 105 || {{nowrap|{{convert|74 x 105|mm|1|abbr=values|disp=out}}}} {{anchor|A7}} || 1/2{{sup|7}} ≈ {{round|0.0078125|4}}
|    88 × 125 || {{nowrap|{{convert|88 x 125|mm|1|abbr=values|disp=out}}}} {{anchor|B7}} || 2{{sup|−{{frac|6|1|2}}}} ≈  {{round|0.0110485435|4}}
|    81 × 114 || {{nowrap|{{convert|81 x 114|mm|1|abbr=values|disp=out}}}} {{anchor|C7}} || 2{{sup|−{{frac|6|3|4}}}} ≈  {{round|0.0092906806|4}}
|-
! 8
|     52 × 74 || {{nowrap|{{convert|52 x 74|mm|1|abbr=values|disp=out}}}} {{anchor|A8}} || 1/2{{sup|8}} ≈ {{round|0.00390625|4}}
|     62 × 88 || {{nowrap|{{convert|62 x 88|mm|1|abbr=values|disp=out}}}} {{anchor|B8}} || 2{{sup|−{{frac|7|1|2}}}} ≈  {{round|0.0055242717|4}}
|     57 × 81 || {{nowrap|{{convert|57 x 81|mm|1|abbr=values|disp=out}}}} {{anchor|C8}} || 2{{sup|−{{frac|7|3|4}}}} ≈  {{round|0.0046453403|4}}
|-
! 9
|     37 × 52 || {{nowrap|{{convert|37 x 52|mm|1|abbr=values|disp=out}}}} {{anchor|A9}} || 1/2{{sup|9}} ≈ {{round|0.001953125|4}}
|     44 × 62 || {{nowrap|{{convert|44 x 62|mm|1|abbr=values|disp=out}}}} {{anchor|B9}} || 2{{sup|−{{frac|8|1|2}}}} ≈  {{round|0.0027621359|4}}
|     40 × 57 || {{nowrap|{{convert|40 x 57|mm|1|abbr=values|disp=out}}}} {{anchor|C9}} || 2{{sup|−{{frac|8|3|4}}}} ≈  {{round|0.0023226701|4}}
|-
! 10
|     26 × 37 || {{nowrap|{{convert|26 x 37|mm|1|abbr=values|disp=out}}}} {{anchor|A10}} || 1/2{{sup|10}} ≈ {{round|0.0009765625|5}}
|     31 × 44 || {{nowrap|{{convert|31 x 44|mm|1|abbr=values|disp=out}}}} {{anchor|B10}} || 2{{sup|−{{frac|9|1|2}}}} ≈  {{round|0.0013810679|4}}
|     28 × 40 || {{nowrap|{{convert|28 x 40|mm|1|abbr=values|disp=out}}}} {{anchor|C10}} || 2{{sup|−{{frac|9|3|4}}}} ≈  {{round|0.0011613351|4}}
|-
!''i''
| colspan=3| <math>\left(\alpha_A\cdot r^{i+1}\right) \times \left(\alpha_A\cdot r^{i}\right),</math> where {{pb}}<math>\alpha_A = \sqrt[4]{2}\,\text{m}; r=\tfrac{1}{\sqrt{2}}</math>
| colspan=3| <math>\left(\alpha_B\cdot r^{i+1}\right) \times \left(\alpha_B\cdot r^{i}\right),</math> where {{pb}}<math>\alpha_B = \sqrt{2}\,\text{m}; r=\tfrac{1}{\sqrt{2}}</math>
| colspan=3| <math>\left(\alpha_C\cdot r^{i+1}\right) \times \left(\alpha_C\cdot r^{i}\right),</math> where {{pb}}<math>\alpha_C = \sqrt[8]{8}\,\text{m}; r=\tfrac{1}{\sqrt{2}}</math>
|}

The <math>\alpha</math> variables are the distinct first terms in the three [[geometric progression]]s of the same ''common ratio'' equal to the square root of two. Each of the three geometric progressions (corresponding to the three [[#ISO A|series A]], [[#ISO B|B]], and [[#ISO C|C]]) is formed by all possible paper dimensions (length and width) of the series arranged in decreasing order. This interesting arrangement of dimensions is also very useful—not only does it form a geometric progression with easy-to-remember formulae, but also each consecutive pair of values (like a sliding window of size 2) will automatically correspond to the dimensions of a standard paper format in the series.

The [[tolerances]] specified in the standard are

* ±{{cvt|1.5|mm|in}} for dimensions up to {{cvt|150|mm|in}},
* ±{{cvt|2|mm|in}} for lengths in the range {{cvt|150 to 600|mm|in}} and
* ±{{cvt|3|mm|in}} for any dimension above {{cvt|600|mm|in}}.

=== Related regional sizes ===

====German original<span class="anchor" id="DIN D"></span><span class="anchor" id="DIN 2A0"></span><span class="anchor" id="DIN 4A0"></span><span class="anchor" id="ISO 2A0"></span><span class="anchor" id="ISO 4A0"></span><span class="anchor" id="German extensions"></span>====

The German standard DIN 476 was published on 18 August 1922 and is the original specification of the [[#DIN A|A]], [[#DIN B|B]] and [[#DIN C|C sizes]]. In 1991, it was split into DIN 476-1 for the A and B formats and 476-2 for the C series. The former has been withdrawn in 2002 in favour of adopting the international standard as DIN EN ISO 216, but part 2 has been retained and was last updated in 2008.

The first and the second editions of DIN 476 from 1922 and 1925 also included a D series.

{| class="wikitable"
|+ DIN D series paper sizes in portrait view (with rounded inch values)
! Format
!colspan="2"| [[#DIN D|D series]]
|-
! Size
! mm × mm || inch × inch
|-
! 0
| {{size|771|1090}}
|-
! 1
| {{size|545|771}}
|-
! 2
| {{size|385|545}}
|-
! 3
| {{size|272|385}}
|-
! 4
| {{size|192|272}}
|-
! 5
| {{size|136|192}}
|-
! 6
| {{size|96|136}}
|-
! 7
| {{size|68|96}}
|-
! 8
| {{size|48|68}}
|}

The smallest formats in the original specifications for each series were A13, B13, C8, and D8. Sizes A11 through A13 were no longer listed in the 1930 edition, nor were B11 through B13. C9 and C10 were added in the 1976 revision for compatibility with photography sizes: C8 closely matches [[photo print sizes|6×9 photos]], and C9 and C10 closely match 7×7 and 5×5 [[diapositive|slides]], respectively.

{| class="wikitable"
|+ DIN 476:1922 tiny formats (with rounded inch values)
! Format !!colspan=2| A !!colspan=2| B
|-
! Size !! mm × mm || inch × inch !! mm × mm || inch × inch
|-
! 11
| {{size|18|26}}
| {{size|22|31}}
|-
! 12
| {{size|13|18}}
| {{size|15|22}}
|-
! 13
| {{size|9|13}}
| {{size|11|15}}
|}

DIN 476 provides for formats larger than A0, denoted by a prefix factor. In particular, it lists the formats 2A0 and 4A0, which are twice and four times the size of A0 respectively. However, ISO 216:2007 notes 2A0 and 4A0 in the table of ''Main series of trimmed sizes'' (ISO A series) as well: "The rarely used sizes [2A0 and 4A0] which follow also belong to this series."

{| class="wikitable"
|+ DIN 476 overformats (with rounded inch values)
! Name !! mm × mm !! inch × inch
|-
! 4A0
| {{size|1682|2378}}
|-
! 2A0
| {{size|1189|1682}}
|}

DIN 476 also used to specify slightly tighter tolerances than ISO 216:

* ±{{cvt|1|mm|in}} for dimensions up to {{cvt|150|mm|in}},
* ±{{cvt|1.5|mm|in}} for lengths in the range {{cvt|150 to 600|mm|in}} and
* ±{{cvt|2|mm|in}} for any dimension above {{cvt|600|mm|in}}.

There used to be a standard, DIN 198, that was just a table of recommended A series formats for a number of business applications. The 1976 edition of this standard introduced a size '''{{frac|2|3}} A4''' {{resx|198 mm|210 mm}} and suggested it for some forms and slips.{{citation needed|date=February 2025}}

====Swedish extensions<span class="anchor" id="SIS D"></span><span class="anchor" id="SIS E"></span><span class="anchor" id="SIS F"></span><span class="anchor" id="SIS G"></span>====
[[File:Comparison SIS 014711 paper sizes.svg|thumb|upright=0.9|Comparison of ISO 216 and Swedish standard SIS 014711 paper sizes between A4 and A3 sizes]]

The Swedish standard [[Swedish Standards Institute|SIS]] 01 47 11<ref name="ss014711">{{cite web |title=Papper—Formatserier A-G |url=https://www.sis.se/en/produkter/standardization/information-sciences-publishing/documents-in-administration-commerce-and-industry/ss14711/ |work=Svensk standard SS 01 47 11 Utgåva 2 |at=Page 2 Figur 1 - Serieformaten exemplifierade |publisher=Swedish Standards Institute |access-date=25 December 2019 |archive-url=https://web.archive.org/web/20131101094445/http://www.sis.se/pappersteknik/pappersprodukter/ss-14711 |archive-date=1 November 2013 |url-status=live}}{{subscription required}}</ref> generalized the ISO system of [[#ISO A|A]], [[#ISO B|B]], and [[#ISO C|C]] formats by adding D, E, F, and G formats to it. Its D format sits between a B format and the next larger A format (just like C sits between A and the next larger B). The remaining formats fit in between all these formats, such that the [[bit-reversal_permutation#Example|sequence of formats]] A4, E4, C4, G4, B4, F4, D4, *H4, A3 is a [[geometric progression]], in which the dimensions grow by a factor <math>\sqrt[16]{2}</math> from one size to the next. However, this SIS standard does not define any size between a D format and the next larger A format (called *H in the previous example).

Of these additional formats, G5 (169 × 239&nbsp;mm) and E5 (155 × 220&nbsp;mm) are popular in Sweden and the Netherlands for printing dissertations,<ref>{{Cite web|url=http://ki.se/content/1/c6/05/90/62/Typography_en.pdf |publisher=Karolinska University Press |title=Typography and readability – a guideline |access-date=19 October 2012 |archive-url=https://web.archive.org/web/20131101001357/http://ki.se/content/1/c6/05/90/62/Typography_en.pdf |archive-date=1 November 2013}}</ref> but the other formats have not turned out to be particularly useful in practice. They have not been adopted internationally and the Swedish standard has been withdrawn.

The Swedish and [[#DIN D|German D series]] basically contain the same sizes but are offset by one, i.e. DIN D4 equals SIS D5 and so on.

{| class="wikitable"
|+ SIS 014711 formulas,<ref>{{cite web |url=http://home.comcast.net/~tamivox/dave/IntlPaper/index.html |archive-url=https://archive.today/20140701234154/http://home.comcast.net/~tamivox/dave/IntlPaper/index.html |url-status=dead |archive-date=1 July 2014 |author-first=Dave |author-last=Barber |title=International paper sizes. A, B, C and D series |date=8 May 2012}}</ref> including the missing step, series *H, between D and A,{{pb}}
<math display="inline">n = 0..10, r = \sqrt[16]{2}, s = \sqrt{\frac{1}{2}}</math>
|-
! Designation
! Shorter edge
! Longer edge
|-
! A''n''
| ''r''{{sup|−4}} × ''s''{{sup|''n''}}
| ''r''{{sup|+4}} × ''s''{{sup|''n''}}
|-
! E''n''
| ''r''{{sup|−3}} × ''s''{{sup|''n''}}
| ''r''{{sup|+5}} × ''s''{{sup|''n''}}
|-
! C''n''
| ''r''{{sup|−2}} × ''s''{{sup|''n''}}
| ''r''{{sup|+6}} × ''s''{{sup|''n''}}
|-
! G''n''
| ''r''{{sup|−1}} × ''s''{{sup|''n''}}
| ''r''{{sup|+7}} × ''s''{{sup|''n''}}
|-
! B''n''
| ''r''{{sup|0}} × ''s''{{sup|''n''}}
| ''r''{{sup|+8}} × ''s''{{sup|''n''}}
|-
! F''n''
| ''r''{{sup|+1}} × ''s''{{sup|''n''}}
| ''r''{{sup|+9}} × ''s''{{sup|''n''}}
|-
! D''n''
| ''r''{{sup|+2}} × ''s''{{sup|''n''}}
| ''r''{{sup|+10}} × ''s''{{sup|''n''}}
|-
!title="Not part of the Swedish standard"| *H''n''
| ''r''{{sup|+3}} × ''s''{{sup|''n''}}
| ''r''{{sup|+11}} × ''s''{{sup|''n''}}
|-
! A(''n''-1)
| ''r''{{sup|+4}} × ''s''{{sup|''n''}}
| ''r''{{sup|+12}} × ''s''{{sup|''n''}}
|}

{| class="wikitable"
|+ Swedish D through G series
! ''n'' !!style="display:none"|     A      !! '''E'''  !!style="display:none"|     C     !!  '''G'''  !!style="display:none"|     B     !!  '''F'''  !!  '''D'''  !!style="display:none"|    *H
|-
! 0 
|style="display:none"| 841 × 1189|| 878 × 1242||style="display:none"| 917 × 1297|| 958 × 1354||style="display:none"|1000 × 1414||1044 × 1477||1091 × 1542||style="display:none"|1139 × 1610
|-
! 1 
|style="display:none"| 595 × 841 || 621 × 878 ||style="display:none"| 648 × 917 || 677 × 958 ||style="display:none"| 707 × 1000|| 738 × 1044|| 771 × 1091||style="display:none"| 805 × 1139
|-
! 2 
|style="display:none"| 420 × 595 || 439 × 621 ||style="display:none"| 459 × 648 || 479 × 677 ||style="display:none"| 500 × 707 || 522 × 738 || 545 × 771 ||style="display:none"| 569 × 805
|-
! 3 
|style="display:none"| 297 × 420 || 310 × 439 ||style="display:none"| 324 × 459 || 339 × 479 ||style="display:none"| 354 × 500 || 369 × 522 || 386 × 545 ||style="display:none"| 403 × 569
|-
! 4 
|style="display:none"| 210 × 297 || 220 × 310 ||style="display:none"| 229 × 324 || 239 × 339 ||style="display:none"| 250 × 354 || 261 × 369 || 273 × 386 ||style="display:none"| 285 × 403
|-
! 5 
|style="display:none"| 149 × 210 || 155 × 220 ||style="display:none"| 162 × 229 || 169 × 239 ||style="display:none"| 177 × 250 || 185 × 261 || 193 × 273 ||style="display:none"| 201 × 285
|-
! 6 
|style="display:none"| 105 × 149 || 110 × 155 ||style="display:none"| 115 × 162 || 120 × 169 ||style="display:none"| 125 × 177 || 131 × 185 || 136 × 193 ||style="display:none"| 142 × 201
|-
! 7 
|style="display:none"|  74 × 105 ||  78 × 110 ||style="display:none"|  81 × 115 ||  85 × 120 ||style="display:none"|  88 × 125 ||  92 × 131 ||  96 × 136 ||style="display:none"| 101 × 142
|-
! 8 
|style="display:none"|  53 ×  74 ||  55 ×  78 ||style="display:none"|  57 ×  81 ||  60 ×  85 ||style="display:none"|  63 ×  88 ||  65 ×  92 ||  68 ×  96 ||style="display:none"|  71 × 101
|-
! 9 
|style="display:none"|  37 ×  53 ||  39 ×  55 ||style="display:none"|  41 ×  57 ||  42 ×  60 ||style="display:none"|  44 ×  63 ||  46 ×  65 ||  48 ×  68 ||style="display:none"|  50 ×  71
|-
!10 
|style="display:none"|  26 ×  37 ||  27 ×  39 ||style="display:none"|  29 ×  41 ||  30 ×  42 ||style="display:none"|  31 ×  44 ||  33 ×  46 ||  34 ×  48 ||style="display:none"|  36 ×  50
|}

====Japanese variation<span class="anchor" id="JIS B}"></span><span class="anchor" id="Japanese B-series variant"></span>====

The Japanese standard [[Japanese Industrial Standards|JIS P 0138]] defines two main series of paper sizes. The JIS A-series is identical to the [[#ISO A|ISO A-series]] except that it has slightly different tolerances. The area of B-series paper is 1.5 times that of the corresponding A-paper (instead of the factor <math>\sqrt{2} = 1.414...</math> for the [[#ISO B|ISO B-series]]), so the length ratio is approximately 1.22 times the length of the corresponding A-series paper. The aspect ratio of the paper is the same as for the A-series paper. Both A- and B-series paper are widely available in Japan, [[Taiwan]] and China, and most photocopiers are loaded with at least A4 and either one of A3, B4, and B5 paper.

[[Cascading Style Sheets]] (CSS) only supports the most popular of the Japanese sizes, ''JIS-B4'' and ''JIS-B5''.<ref name="mozilla.org"/>

{| class="wikitable"
|+ JIS B series paper sizes (with rounded inch values)
! Size !! mm × mm || inch × inch
|-
! 0
| {{size|1030|1456}}
|-
! 1
| {{size|728|1030}}
|-
! 2
| {{size|515|728}} 
|-
! 3
| {{size|364|515}} 
|-
! 4
| {{size|257|364}} 
|-
! 5
| {{size|182|257}} 
|-
! 6
| {{size|128|182}} 
|-
! 7
| {{size|91|128}}
|-
! 8
| {{size|64|91}}
|-
! 9
| {{size|45|64}}
|-
! 10
| {{size|32|45}}
|-
! 11
| {{size|22|32}}
|-
! 12
| {{size|16|22}}
|}

{| class="wikitable"
|+ JIS P 0202 raw sizes (with rounded inch values)
! Size !! mm × mm || inch × inch ||title="aspect ratio"| AR || sun × sun
|-
!title="Between ISO RA1 and SRA1"| A ({{lang|ja|列本判}})
| {{size|625|880|ar=on}} || {{resx|20.6|29}}
|-
!title="JIS B1 oversize"| B ({{lang|ja|列本判}})
| {{size|765|1085|ar=on}} || {{resx|25.25|35.8}}
|-
! {{nihongo||四六判|Shiroku-ban}} (4-6)
| {{size|788|1091|ar=on}} || {{resx|26|36}}
|-
! {{nihongo3|Chrysanthemum|菊判|Kiku-ban}}
| {{size|636|939|ar=on}} || {{resx|21|31}}
|-
! {{nihongo||ハトロン判|Hattron}}
| {{size|900|1200|ar=on}} || {{resx|29.7|39.6}}
|}

A popular size for books, dubbed AB, combines the shorter edges of A4 and B4. Another two with an aspect ratio approximating [[16:9]] are 20% narrower variants of A6 and B6, respectively, the latter resulting from cutting JIS B1 into {{resx|4|10}} sheets (thus "B40").

There are also a number of traditional paper sizes, which are now used mostly by printers. The most common of these old series is the {{transliteration|ja|[[#K|Shiroku-ban]]}} and the {{transliteration|ja|Kiku}} paper sizes.

{| class="wikitable"
|+ Other Japanese paper sizes (with rounded inch values){{qn|date=January 2020}}
! Size
! mm × mm || inch × inch !!title="aspect ratio"| AR !! sun × sun !! Notes
|-
! AB
| {{size|210|257|ar=on}}
| {{resx|6.93|8.48}} || {{resx|A4/A5|JIS B4/B5}}
|-
! B40
| {{size|103|182|ar=16:9}} || {{resx|3.4|6}}
| JIS B1 {{resx|{{frac|height|10}}|{{frac|width|4}}}}
|-
! 35
| {{size|84|148|ar=16:9}} || {{resx|2.77|4.88}} 
| Trimmed {{resx|3|5}}<!--?-->
|-
!rowspan=4| {{transliteration|ja|Kiku-ban}}
| {{size|227|304|ar=on}} || {{resx|7.5|10}} <!--secondary variant according to Japanese Wikipedia, previously listed with 306 mm-->
|-
| {{size|218|304|ar=on}} || {{resx|7.2|10}}
|-
| {{size|152|227|ar=on}} || {{resx|5|7.5}} <!--secondary variant, previously listed with 151 mm-->
|-
| {{size|152|218|ar=on}} || {{resx|5|7.2}}
|}

====Chinese extensions<span class="anchor" id="GB/T 148"></span>====

The Chinese standard GB/T 148–1997,<ref>{{Cite web |url=http://www.gb688.cn/bzgk/gb/newGbInfo?hcno=20746CFEE63514B24DD64A415CB65377 |script-title=zh:国家标准 {{!}} GB/T 148-1997 |date=26 May 1997 |website=Standardization Administration of China |access-date=13 April 2017 |archive-url=https://web.archive.org/web/20170413154251/http://www.gb688.cn/bzgk/gb/newGbInfo?hcno=20746CFEE63514B24DD64A415CB65377 |archive-date=13 April 2017 |url-status=dead }}</ref> which replaced GB 148–1989, documents the standard ISO series, A and B, but adds a custom D series. This Chinese format originates from the [[Republic of China (1912–1949)]]. The D series is not identical to the German or Swedish D series. It does not strictly follow the same principles as ISO paper sizes: The aspect ratio is only very roughly <math>\sqrt{2}</math>. The short side of the size is always 4&nbsp;mm longer than the long side of the next smaller size. The long side of the size is always exactly &ndash; i.e. without further rounding &ndash; twice as long as the short side of the next smaller size.

{| class="wikitable"
|+ [[Standardization Administration of China|SAC]] paper sizes (with rounded inch values and raw sizes)
! Format
!colspan=2| D series
!rowspan=2 title="aspect ratio"| AR
!rowspan=2| Alias
!colspan=2| Untrimmed sizes
|-
! Size
! mm × mm || inch × inch
! mm × mm || inch × inch
|-
! 0
| {{size|764|1064}}
| 1.3927
| 1K
| {{size|780|1080}}
|-
! 1
| {{size|532|760}}
| 1.4286
| 2K
| {{size|540|780}}
|-
! 2
| {{size|380|528}}
| 1.3895
| 4K
| {{size|390|540}}
|-
! 3
| {{size|264|376}}
| 1.{{overline|4242}}
| 8K
| {{size|270|390}}
|-
! 4
| {{size|188|260}}
| 1.3830
| 16K
| {{size|195|270}}
|-
! 5
| {{size|130|184}}
| 1.4154
| 32K
| {{size|135|195}}
|-
! 6
| {{size|92|126}}
| 1.3696
| 64K
| {{size|97|135}}
|}

==== Indian variants ====
The ''Bureau of Indian Standards'' recommends the "ISO-A series" size of drawing sheet for engineering drawing works. The Bureau of Indian Standards specifies all the recommendations for engineering drawing sheets in its bulletin IS 10711: 2001.<ref>{{Cite book|url=https://law.resource.org/pub/in/bis/S01/is.sp.46.2003.pdf|title=SP 46 (2003): Engineering Drawing Practice for Schools and Colleges |publisher=Bureau of Indian Standards |isbn=81-7061-019-2 |date=Jul 2003 |url-status=live |archive-url=https://web.archive.org/web/20230909054902/https://law.resource.org/pub/in/bis/S01/is.sp.46.2003.pdf |archive-date= Sep 9, 2023 }}</ref>

The Bureau extended the ISO-A series with a '''Special Elongated Sizes''' (Second Choice). These sizes are achieved by increasing the shorter dimensions of a sheet of the ISO A series to lengths that are multiples of the shorter dimensions of the chosen basic sheet; in effect, all of the Indian elongated sizes emulate having several regular-size sheets joined on their long edge.

{| class="wikitable"
|+ IS Special Elongated Sizes (Second Choice) with rounded inch values
! Size !! mm × mm !! in × in !!title="aspect ratio"| AR
|-
! A3 x 3
| {{size|420|891|ar=on}} 
|-
! A3 x 4
| {{size|420|1189|ar=on}}
|-
! A4 x 3
| {{size|297|630|ar=on}}
|-
! A4 x 4
| {{size|297|841|ar=on}}
|-
! A4 x 5
| {{size|297|1051|ar=on}}
|}

There is also a '''Exceptional Elongated Sizes''' (Third Choice). These sizes are obtained by increasing the shorter dimensions of a sheet of the ISO-A series to lengths that are multiples of the shorter dimensions of the chosen basic sheet. These sizes are used when a very large or extra elongated sheet is needed.

{| class="wikitable"
|+ IS Exceptional Elongated Sizes (Third Choice) with rounded inch values
! Size !! mm × mm !! in × in !!title="aspect ratio"| AR
|-
! A0 x 2
| {{size|1189|1682|ar=2:√2}} 
|-
! A0 x 3
| {{size|1189|2523|ar=on}}
|-
! A1 x 3
| {{size|841|1783|ar=on}}
|-
! A1 x 4
| {{size|841|2378|ar=on}}
|-
! A2 x 3
| {{size|594|1261|ar=on}}
|-
! A2 x 4
| {{size|594|1682|ar=on}}
|-
! A2 x 5
| {{size|594|2102|ar=on}}
|-
! A3 x 5
| {{size|420|1486|ar=on}}
|-
! A3 x 6
| {{size|420|1783|ar=on}}
|-
! A3 x 7
| {{size|420|2080|ar=on}}
|-
! A4 x 6
| {{size|297|1261|ar=on}}
|-
! A4 x 7
| {{size|297|1471|ar=on}}
|-
! A4 x 8
| {{size|297|1682|ar=on}}
|-
! A4 x 9
| {{size|297|1892|ar=on}}
|}

====Soviet variants<span class="anchor" id="OST 303"></span><span class="anchor" id="OST 5115"></span>====

The first standard of paper size in the Soviet Union was OST 303 in 1926. Six years later, it was replaced by OST 5115 which generally followed DIN 476 principles, but used Cyrillic lowercase letters instead of Latin uppercase, had the second row shifted so that б<sub>0</sub> (B0) roughly corresponded to B1 and, more importantly, had slightly different sizes:<ref>{{Cite web |last=Митяев |first=К. Г. |date=1946 |title=Теория и практика архивного дела |trans-title=Theory and practice of archiving |url=http://www.spsl.nsc.ru/FullText/Книги/Уст.%20902%20М.678/Уст.%20902%20М.678.pdf |url-status=dead |archive-url=https://web.archive.org/web/20200208012944/http://www.spsl.nsc.ru/FullText/%D0%9A%D0%BD%D0%B8%D0%B3%D0%B8/%D0%A3%D1%81%D1%82.%20902%20%D0%9C.678/%D0%A3%D1%81%D1%82.%20902%20%D0%9C.678.pdf |archive-date=2020-02-08 |access-date=2022-07-15}}</ref>

{| class="wikitable"
|+ OST 5115 formats (1932)
! Format !!colspan=2| а (A) !!colspan=2| б (B) !!colspan=2| в (V, C)
|-
! Size 
! mm × mm !! inch × inch
! mm × mm !! inch × inch
! mm × mm !! inch × inch
|-
! 0
| {{size|814|1152}} || {{size|747|1056}} ||colspan=2|
|-
! 1
| {{size|576|814}}|| {{size|528|747}}|| {{size|628|888}}
|-
! 2
| {{size|407|576}}|| {{size|373|528}}|| {{size|444|628}}
|-
! 3
| {{size|288|407}}|| {{size|264|373}}|| {{size|314|444}}
|-
! 4
| {{size|203|288}}|| {{size|186|264}}|| {{size|222|314}}
|-
! 5
| {{size|144|203}}|| {{size|132|186}}|| {{size|157|222}}
|-
! 6
| {{size|101|144}}|| {{size|93|132}}|| {{size|111|157}}
|-
! 7
| {{size|72|101}}|| {{size|66|93}}|| {{size|78|111}}
|-
! 8
| {{size|50|72}}|| {{size|46|66}}|| {{size|55|78}}
|-
! 9
| {{size|36|50}}|| {{size|33|46}}|| {{size|39|55}}
|-
! 10
| {{size|25|36}}|| {{size|23|33}} ||colspan=2 rowspan=4|
|-
! 11
| {{size|18|25}}|| {{size|16|23}}
|-
! 12
| {{size|12|18}}|| {{size|11|16}}
|-
! 13
| {{size|9|12}} ||colspan=2|
|}

The general adaptation of ISO 216 in the Soviet Union, which replaced OST 5115, was GOST 9327. In its 1960 version, it lists formats down to A13, B12 and C8 and also specifies {{frac|1|2}}, {{frac|1|4}} and {{frac|1|8}} prefixes for halving the shorter side (repeatedly) for stripe formats, e.g. {{frac|1|2}}A4 = 105&nbsp;mm × 297&nbsp;mm.

[[File:Old Soviet standard for paper sizes.svg|thumb|A1, A2, A3, A4 and non-ISO sizes as GOST 3450-60 formats]]
A standard for technical drawings from 1960, GOST 3450,<ref>{{cite web |url=http://weldworld.ru/theory/cherchenie/formaty.html#link2 |title=Formaty |script-title=ru:Форматы |trans-title=Formats |website=Мир Сварки |language=ru |access-date=2 December 2017 |archive-url=https://web.archive.org/web/20171202203209/http://weldworld.ru/theory/cherchenie/formaty.html#link2 |archive-date=2 December 2017 |url-status=live}}</ref> introduces alternative numeric format designations to deal with very high or very wide sheets.
These 2-digit codes are based upon A4 = "11": The first digit is the factor the longer side (297&nbsp;mm) is multiplied by and the second digit is the one for the shorter side (210&nbsp;mm), so "24" is 2×297&nbsp;mm × 4×210&nbsp;mm = 594&nbsp;mm × 840&nbsp;mm.

{| class="wikitable"
|+ Soviet formats with multiplied shorter side (mm×mm)
|-
| ''n''
! (×1) !! ×2 !! ×3 !! ×4 !! ×5 !! ×6
|-
!title="4·4n"| 5
|title="4·4"| = A0 ||title="4·8"| = 2A0||title="4·12"|2523 × 1189||title="4·16"|3364 × 1189||title="4·20"|4204 × 1189 ||title="4·24"|5045 × 1189
|-
!title="2n·4"| 4
|title="2·4"| = A1 ||title="4·4"| = A0 ||title="6·4"|1784 × 841 ||title="8·4"|2378 × 841 ||title="10·4"|2973 × 841 ||title="12·4"|3568 × 841
|-
!title="2·2n"| 3
|title="2·2"| = A2 ||title="2·4"| = A1  ||title="2·6"|1261 × 595 ||title="2·8"|1682 × 595 ||title="2·10"|2102 × 595 ||title="2·12"|2523 × 595
|-
!title="n·2"|  2 
|title="1·2"| = A3 ||title="2·2"| = A2  ||title="3·2"| 892 × 420 ||title="4·2"|1189 × 420 ||title="5·2"|1487 × 420 ||title="6·2"|1784 × 420
|-
!title="1·n"| 1
|title="1·1"| = A4 ||title="1·2"| = A3  ||title="1·3"| 631 × 297 ||title="1·4"| 841 × 297 ||title="1·5"|1051 × 297 ||title="1·6"|1261 × 297
|-
!title="{{frac|1|2}}n·1"| 0
|title="{{frac|1|2}}·1"| = A5 ||title="1·1"| = A4  ||title="{{frac|1|1|2}}·1"|446 × 210 ||title="2·1"| 595 × 210 ||title="{{frac|2|1|2}}·1"| 743 × 210 ||title="3·1"| 892 × 210
|}

[[File:GOST 2301-68.svg|thumb|A2, A3, A4 and some derived non-ISO sizes as GOST 2301-68 formats]]
GOST 3450 from 1960 was replaced by ESKD GOST 2301 in 1968,<ref>{{cite web |url=http://graph.power.nstu.ru/wolchin/umm/eskd/eskd/GOST/2_301.htm |script-title=ru:Форматы (ЕСКД ГОСТ 2.301-68) |title=Formaty (ESKD GOST 2.301-68) |trans-title=Formats |website=Единая Система Конструкторской Документации |language=ru |access-date=2 December 2017 |archive-url=https://web.archive.org/web/20161201015706/http://graph.power.nstu.ru/wolchin/umm/eskd/eskd/GOST/2_301.htm |archive-date=1 December 2016 |url-status=live}}</ref> but the numeric designations remained in popular use much longer.
The new designations were not purely numeric but consisted of the ISO label followed by an 'x', or possibly the multiplication sign '×', and the factor, e.g. DIN 2A0 = GOST A0×2, but DIN 4A0 ≠ GOST A0×4, also listed are: A0×3, A1×3, A1×4, A2×3–A2×5, A3×3–A3×7, A4×3–A4×9. The formats ...×1 and ...×2 usually would be aliases for existing formats.

===Elongated sizes<span class="anchor" id="ISO 5457"></span>===

ISO 5457, last updated in 1999,<ref name="iso5457">{{Cite web|url=https://www.iso.org/standard/29017.html |title=ISO 5457:1999|website=ISO}}</ref> introduces elongated sizes that are formed by a combination of the dimensions of the short side of an A-size (e.g. A2) with the dimensions of the long side of another larger A-size (e.g. A0). The result is a new size, for example with the abbreviation A2.0 we would have a {{resx|420|1189}} mm size.

[[File:ISO 5457 elongated paper sizes.svg|alt=elongated ISO paper sizes|thumb|Elongated paper sizes schema]]
{| class="wikitable"
|+ ISO 5457 elongated paper sizes
! Size !! Short edge !! Long edge !! mm × mm !! in × in !!title="aspect ratio"| AR
|-
! A1.0
| A1/A2 || A0
| {{size|594|1189|ar=2:1}}
|-
! A2.0
|rowspan=2| A2/A3 || A0
| {{size|420|1189|ar=2√2:1}}
|-
! A2.1
| A1/A0
| {{size|420|841|ar=2:1}}
|-
! A3.0
|rowspan=3| A3/A4 || A0
| {{size|297|1189|ar=4:1}}
|-
! A3.1
| A1/A0
| {{size|297|841|ar=2√2:1}}
|-
! A3.2
| A2/A1
| {{size|297|594|ar=2:1}}
|}

These drawing paper sizes have been adopted by [[ANSI/ASME Y14.1|ANSI/ASME Y14.1M]] for use in the United States, alongside A0 through A4 and alongside inch-based sizes.

=== International envelope and insert sizes ===
{{main|Envelope#Sizes}}

{| class="wikitable"
|+ Common folded or cut sizes of ISO paper: stripe formats and inserts
|-
! Name
! mm × mm !! inch × inch !!title="aspect ratio"| AR
! Notes
|-
! {{frac|3}}A4
| {{size|99|210|ar=on}}
| common flyer or stripe size
|-
! ''unnamed''
| {{size|105|210|ar=on}}
| standard folded size of German letters
|}

[[File:DIN_5008,_Form_A.svg|thumb|DIN 5008 Form A]]
DIN 5008 (previously DIN 676) prescribes, among many other things, two variants, A and B, for the location of the address field on the first page of a business letter and how to fold the A4 sheet accordingly, so the only part visible of the main content is the subject line.

{| class="wikitable"
|+ Common envelopes for ISO paper, that are not simple C-series and B-series formats
|-
! Name
! mm × mm !! inch × inch !!title="aspect ratio"| AR
! Content
! Notes
|-
! DL
| {{size|110|220|ar=on}}
|rowspan=3| {{frac|3}}A4, DIN 5008 A and B
| ''Designated long'', "DIN lang" ([[Deutsches Institut für Normung|DIN]] long); sometimes erroneously instead called "DLE", apparently for ''envelope''; exactly matches Swedish SIS E6/E5 (E6: {{resx|110 mm|155 mm}}, E5: {{resx|155 mm|220 mm}}); envelope #5 in China, Chou/N 6 in Japan; fits well enclosed in C6/C5 for the purpose of e.g. reply mail
|-
! C6/C5
| {{size|114|229|ar=2}}
| Common edge of C6 and C5 is 161&nbsp;mm; also known as "Postfix", "DL+" or "DL Max", but those terms are not standardized
|-
! Italian 
| {{size|110|230|ar=2.1}}
| Centimetre-rounded C6/C5 or slightly wider DL
|-
! C7/C6 
| {{size|81|162|ar=on}}
| {{frac|3}}A5
| Common edge of C7 and C6 is 114&nbsp;mm 
|-
! B6/C4 
| {{size|125|324|ar=2.6}}
| 
| B6 is {{resx|125 mm|176 mm}}, C4 is {{resx|229 mm|324 mm}}
|-
! Invite
| {{size|220|220|ar=on}}
| Square card with edge of A4 and A5, 210&nbsp;mm
| 
|-
! DIN E4
| {{size|280|400|ar=on}}
| 
| Listed in DIN 476–2, but not part of a series proper; SIS E4 is {{resx|220 mm|310 mm}}
|}

===International raw sizes<span class="anchor" id="ISO 217"></span><span class="anchor" id="ISO 2784"></span>===

{| class="wikitable"
|+ ISO 217 raw and ISO 5457 untrimmed sheet sizes
|-
! Raw
! mm × mm !! inch × inch
! Special raw
! mm × mm !! inch × inch
! Untrimmed
! mm × mm !! inch × inch
! Trimmed
! mm × mm !! inch × inch
<!--! drawing area-->
! mm × mm !! inch × inch
|-
! RA0
| {{size|860|1220|p=4}}
! SRA0
| {{size|900|1280|p=4}}
! A0U
| {{size|880|1230|p=4}}
! A0T
| {{size|841|1189|p=4}}
| {{size|821|1159|p=4}}
|-
! RA1
| {{size|610|860|p=4}}
! SRA1
| {{size|640|900|p=4}}
! A1U
| {{size|625|880|p=4}}
! A1T
| {{size|594|841|p=4}}
| {{size|574|811|p=4}}
|-
! RA2
| {{size|430|610|p=4}}
! SRA2
| {{size|450|640|p=4}}
! A2U
| {{size|450|625|p=4}}
! A2T
| {{size|420|594|p=4}}
| {{size|400|564|p=4}}
|-
! RA3
| {{size|305|430|p=4}}
! SRA3
| {{size|320|450|p=4}}
! A3U
| {{size|330|450|p=4}}
! A3T
| {{size|297|420|p=4}}
| {{size|277|390|p=4}}
|-
! {{visible anchor|RA4}}
| {{size|215|305|p=4}}
! SRA4
| {{size|225|320|p=4}}
! A4U
| {{size|240|330|p=4}}
! A4T
| {{size|210|297|p=4}} 
| {{size|180|277|p=4}}
|}

ISO 5457 specifies drawing paper sizes with a trimmed size equal to the A series sizes from A4 upward. The untrimmed sizes are 3 to 4&nbsp;cm larger and rounded to the nearest centimetre. A0 through A3 are used in landscape orientation, while A4 is used in portrait orientation. Designations for pre-printed drawing paper include the base sizes and a suffix, either ''T'' for trimmed or ''U'' for untrimmed sheets.

The withdrawn standard ISO 2784 did specify sizes of continuous, fan-fold forms based upon whole inches as was common for paper in continuous lengths in automatic data processing (ADP) equipment. Specifically, {{convert|12|in|mm}} was considered an untrimmed variant of the A4 height of 297&nbsp;mm.

{| class="wikitable"
|+ ISO 2784:1974 correspondence for continuous ADP paper
!rowspan=2| Size 
!colspan=3| Acceptable equivalent 
!colspan=3| Direct equivalent 
! Exact size
!colspan=2| Gross size 
|-
! inch × inch !! mm × mm !!title="aspect ratio"| AR
! inch × inch !! mm × mm !!title="aspect ratio"| AR
! mm × mm
! mm × mm !! inch × inch
|-
! A4
| {{size|8|12|in|mm|f=4|ar=on}} || {{size|8+1/3|11+2/3|in|mm|f=4|ar=on}} || {{resx|210|297}} ||title="Gross width for A3 is 450 mm, intermediate gross widths of 375 mm and 400 mm have no ISO 216 equivalent" {{size|250|340|p=10}}
|-
! A5
| {{size|6|8|in|mm|f=4|ar=on}} || {{size|5+5/6|8+1/3|in|mm|f=4|ar=on}} || {{resx|148|210}} || {{size|180|250|p=10}}
|-
! A6
| {{size|4|6|in|mm|f=4|ar=on}} || {{size|4+1/6|5+5/6|in|mm|f=4|ar=on}} || {{resx|105|148}} || {{n/a}} || {{n/a}}
|-
! A7
| {{size|3|4|in|mm|f=4|ar=on}} || {{n/a}} || {{n/a}} || {{n/a}} || {{resx|74|105}} || {{n/a}} || {{n/a}}
|}