Mile

The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of length; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised between the Commonwealth of Nations and the United States by an international agreement in 1959, when it was formally redefined with respect to SI units as exactly Template:Nowrap.

With qualifiers, mile is also used to describe or translate a wide range of units derived from or roughly equivalent to the Roman mile (roughly Template:Nowrap), such as the nautical mile (now Template:Nowrap exactly), the Italian mile (roughly Template:Nowrap), and the Chinese mile (now Template:Nowrap exactly). The Romans divided their mile into 5,000 {{#invoke:Lang|lang}} (Template:Lit.), but the greater importance of furlongs in the Elizabethan-era England meant that the statute mile was made equivalent to Template:Nowrap or Template:Nowrap in 1593. This form of the mile then spread across the British Empire, some successor states of which continue to employ the mile. The US Geological Survey now employs the metre for official purposes, but legacy data from its 1927 geodetic datum has meant that a separate US survey mile Template:Nowrap continues to see some use, although it was officially phased out in 2022. While most countries replaced the mile with the kilometre when switching to the International System of Units (SI), the international mile continues to be used in some countries, such as the United Kingdom, the United States, and a number of countries with fewer than one million inhabitants, most of which are UK or US territories or have close historical ties with the UK or US.

Name Template:Anchor

The modern English word mile derives from Middle English {{#invoke:Lang|lang}} and Old English {{#invoke:Lang|lang}}, which was cognate with all other Germanic terms for miles. These derived from the nominal ellipsis form of {{#invoke:Lang|lang}} 'mile' or {{#invoke:Lang|lang}} 'miles', the Roman mile of one thousand paces.Template:Sfnp

The present international mile is usually what is understood by the unqualified term mile. When this distance needs to be distinguished from the nautical mile, the international mile may also be described as a land mile or statute mile.Template:Sfnp In British English, statute mile may refer to the present international mile or to any other form of English mile since the 1593 Act of Parliament, which set it as a distance of Template:Nowrap. Under American law, however, statute mile refers to the US survey mile.Template:Sfnp Foreign and historical units translated into English as miles usually employ a qualifier to describe the kind of mile being used but this may be omitted if it is obvious from the context, such as a discussion of the 2nd-century Antonine Itinerary describing its distances in terms of miles rather than Roman miles.

Abbreviation

The mile has been variously abbreviated in English—with and without a trailing period—as "mi", "M", "ml", and "m".<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The American National Institute of Standards and Technology now uses and recommends "mi" to avoid confusion with the SI metre (m) and millilitre (ml).Template:Sfnp However, derived units such as miles per hour or miles per gallon continue to be abbreviated as "mph" and "mpg" rather than "mi/h" and "mi/gal". In the United Kingdom, road signs use "m" as the abbreviation for mile though height and width restrictions also use "m" as the symbol for the metre, which may be displayed alongside feet and inches.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The BBC style holds that "there is no acceptable abbreviation for 'milesTemplate:'" and so it should be spelled out when used in describing areas.<ref>"Numbers" Template:Webarchive BBC</ref>

Historical

File:RomaForoRomanoMiliariumAureum.JPG

The supposed remains of the Golden Milestone, the zero-mile marker of the Roman road network, in the Roman Forum

Roman

The Roman mile ({{#invoke:Lang|lang}}, Template:Abbr "thousand paces"; Template:Abbr m.p.; also {{#invoke:Lang|lang}}Template:Refn and {{#invoke:Lang|lang}}) consisted of a thousand paces as measured by every other step—as in the total distance of the left foot hitting the ground 1,000 times.<ref>Template:Cite journal</ref> When Roman legionaries were well-fed and harshly driven in good weather, they thus created longer miles. The distance was indirectly standardised by Agrippa's establishment of a standard Roman foot (Agrippa's own) in 29 BC,Template:Sfnp and the definition of a pace as 5 feet. An Imperial Roman mile thus denoted 5,000 Roman feet. Surveyors and specialised equipment such as the decempeda and dioptra then spread its use.Template:Sfn

In modern times, Agrippa's Imperial Roman mile was empirically estimated to have been about Template:Convert in length, slightly less than the Template:Convert of the modern international mile.Template:Sfnp

In Hellenic areas of the Empire, the Roman mile (Template:Langx, {{#invoke:Lang|lang}}) was used beside the native Greek units as equivalent to 8 stadia of 600 Greek feet. The {{#invoke:Lang|lang}} continued to be used as a Byzantine unit and was also used as the name of the zero mile marker for the Byzantine Empire, the Milion, located at the head of the Mese near Hagia Sophia.

The Roman mile spread throughout Europe, with its local variations giving rise to the different units.Template:Citation needed Also arising from the Roman mile is the milestone. All roads radiated out from the Roman Forum throughout the Empire – 50,000 (Roman) miles of stone-paved roads. At every mile was placed a shaped stone. Originally, these were obelisks made from granite, marble, or whatever local stone was available. On these was carved a Roman numeral, indicating the number of miles from the centre of Rome – the Forum. Hence, one can know how far one is from Rome.<ref name="AdkinsAdkins2014">Template:Cite book</ref>

Ptolemaic mile

In the 2nd-century, Greco-Roman polymath, Claudius Ptolemy, of Alexandria (Egypt), in his Almagest and Geography, defined a mile as a geographic arcminute of longitude, of the earths circumference, equivalent to 1:60 of a degree of longitude, or 1:21,600 of the circumference.<ref>Template:Cite journal</ref> While his estimation for the circumference of the earth, and therefore the length of a stade, and a mile, from third party observations, principally offered in non-normalised station (600 Greek feet), Egyptian schoinos, and Persian parasang were erroneous. As were Ptolomy's assumptions of a customary stade to be Template:Sfrac of a Roman mile, Template:Sfrac of a schoinos or parasang, Template:Sfrac of an arc-minute, or ~185 metres,<ref>Template:Cite journal</ref><ref>Template:Cite book</ref> his Geographical mile is the basis of the current nautical mile, and was adopted by medieval Arab and European cartographers.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Italian

The Italian mile ({{#invoke:Lang|lang}}, Template:Abbr {{#invoke:Lang|lang}}) was traditionally considered a direct continuation of the Roman mile, equal to 1000 paces,<ref name=demorgan/> although its actual value over time or between regions could vary greatly.Template:Sfnp It was often used in international contexts from the Middle Ages into the 17th century<ref name=demorgan>Template:Cite journal</ref> and is thus also known as the "geographical mile",<ref>Template:Cite book</ref> although the geographical mile is now a separate standard unit.

Arabic

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The Arabic mile ({{#invoke:Lang|lang}}, {{#invoke:Lang|lang}}), of 4,000 cubits, was not the common Arabic unit of length; instead, Arabs and Persians traditionally used the longer parasang or "Arabic league". Although the precise length of the Arabic mile remains disputed, due to the variability in cubit length, it was somewhere between 1.8 and 2.0 km. The Arabic mile being approximate to a 1.852 km nautical or geographical mile, and an approximation of 1 arcminute of latitude measured directly north-and-south along a meridian. The mile was used by medieval Arab geographers and scientists.

English

The "old English mile" of the medieval and early modern periods varied but seems to have measured about 1.3 international miles (2.1 km).Template:SfnpTemplate:Sfnp The old English mile varied over time and location within England.Template:Sfnp The old English mile has also been defined as 79,200 or 79,320 inches (1.25 or 1.2519 statute miles).Template:Sfnp The English long continued the Roman computations of the mile as 5,000 feet, 1,000 paces, or 8 longer divisions, which they equated with their "furrow's length" or furlong.Template:Sfnp

The origins of English units are "extremely vague and uncertain",Template:Sfnp but seem to have been a combination of the Roman system with native British and Germanic systems both derived from multiples of the barleycorn.Template:Refn Probably by the reign of Edgar in the 10th century, the nominal prototype physical standard of English length was an arm-length iron bar (a yardstick) held by the king at Winchester;Template:SfnTemplate:Sfnp the foot was then one-third of its length. Henry I was said to have made a new standard in 1101 based on his own arm.Template:Sfnp Following the issuance of Magna Carta in 1215, the barons of Parliament directed John and his son to keep the king's standard measure ({{#invoke:Lang|lang}}) and weight at the Exchequer,Template:Sfnp which thereafter verified local standards until its abolition in the 19th century. New brass standards are known to have been constructed under Henry VII and Elizabeth I.Template:Sfnp

Arnold's Template:C. Customs of London recorded a mile shorter than previous ones, coming to 0.947 international miles (5,000 feet) or 1.524 km.Template:Sfnp

Statute

Template:Redirect Template:Anchor The English statute mile was established by a Weights and Measures Act of Parliament in 1593 during the reign of Queen Elizabeth I. The act on the Composition of Yards and Perches had shortened the length of the foot and its associated measures, causing the two methods of determining the mile to diverge.Template:Sfnp Owing to the importance of the surveyor's rod in deeds and surveying undertaken under Henry VIII,Template:Sfnp decreasing the length of the rod by Template:Frac would have amounted to a significant tax increase. Parliament instead opted to maintain the mile of 8 furlongs (which were derived from the rod) and to increase the number of feet per mile from the old Roman value.Template:Sfnp The applicable passage of the statute reads: "A Mile shall contain eight Furlongs, every Furlong forty Poles,Template:Refn and every Pole shall contain sixteen Foot and Template:Not a typo half."Template:Refn The statute mile therefore contained 5,280 feet or 1,760 yards.Template:Sfnp The distance was not uniformly adopted. Robert Morden had multiple scales on his 17th-century maps which included continuing local values: his map of Hampshire, for example, bore two different "miles" with a ratio of Template:NowrapTemplate:Sfnp and his map of Dorset had three scales with a ratio of Template:Nowrap.Template:Sfnp In both cases, the traditional local units remained longer than the statute mile. The English statute mile was superseded in 1959 by the international mile by international agreement.

Welsh

The Welsh mile ({{#invoke:Lang|lang}} or {{#invoke:Lang|lang}}) was 3 statute miles and 1,470 yards long (6.17 km). It comprised 9,000 paces ({{#invoke:Lang|lang}}), each of 3 Welsh feet ({{#invoke:Lang|lang}}) of 9 inches ({{#invoke:Lang|lang}}).Template:Sfnp (The Welsh inch is usually reckoned as equivalent to the English inch.) Along with other Welsh units, it was said to have been codified under Dyfnwal the Bald and Silent and retained unchanged by Hywel the Good.Template:Sfnp Along with other Welsh units, it was discontinued following the conquest of Wales by Edward I of England in the 13th century.

Scots

File:Edinburgh High Street.JPG

Edinburgh's "Royal Mile"—running from the castle to Holyrood Abbey—is roughly a Scots mile long.<ref>Template:Cite book</ref>

The Scots mile was longer than the English mile,<ref name="SNL">Template:Cite book</ref> as mentioned by Robert Burns in the first verse of his poem "Tam o' Shanter". It comprised 8 (Scots) furlongs divided into 320 falls or faws (Scots rods).<ref name="DOST">Template:Cite book</ref> It varied from place to place but the most accepted equivalencies are 1,976 Imperial yards (1.123 statute miles or 1.81 km). It was legally abolished three times: first by a 1685 act of the Scottish Parliament,<ref name="1685-4-83">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> again by the 1707 Treaty of Union with England,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and finally by the Weights and Measures Act 1824.<ref name="SNL" /> It had continued in use as a customary unit through the 18th century but had become obsolete by its final abolition.

Irish

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File:Milestone, Mountbellow (geograph 5365674).jpg

Milestone on Mountbellew Bridge, erected Template:Circa. Distances are given in Irish miles.

The Irish mile ({{#invoke:Lang|lang}} or {{#invoke:Lang|lang}}) measured 2,240 yards: approximately 1.27 statute miles or 2.048 kilometres.Template:Sfnp<ref name=OSIfaq>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It was used in Ireland from the 16th century plantations until the 19th century, with residual use into the 20th century. The units were based on "English measure" but used a linear perch measuring Template:Convert as opposed to the English rod of Template:Convert.<ref name=OSIfaq />

Danish

Following its standardisation by Ole Rømer in the late 17th century, the Danish mile ({{#invoke:Lang|lang}}) was precisely equal to the Prussian mile and likewise divided into 24,000 feet.Template:Sfnp These were sometimes treated as equivalent to 7.5 km. Earlier values had varied: the {{#invoke:Lang|lang}}, for instance, had been 11.13 km.

Dutch

File:Mercator scale.png

Scalebar on a 16th-century map made by Mercator. The scalebar is expressed in "Hours walking or common Flemish miles", and includes three actual scales: small, medium and big Flemish miles.

The Dutch mile ({{#invoke:Lang|lang}}) has had different definitions throughout history. One of the older definitions was 5,600 ells. But the length of an ell was not standardised, so that the length of a mile could range between 3,280 m and 4,280 m. In the sixteenth century, the Dutch had three different miles: small ({{#invoke:Lang|lang}}), medium ({{#invoke:Lang|lang}}), and large ({{#invoke:Lang|lang}}). The Dutch {{#invoke:Lang|lang}} mile had the historical definition of one hour's walking ({{#invoke:Lang|lang}}), which was defined as 24 stadia, 3000 paces, or 15,000 Amsterdam or Rhineland feet (respectively 4,250 m or 4,710 m). The common Dutch mile was 32 stadia, 4,000 paces, or 20,000 feet (5,660 m or 6,280 m). The large mile was defined as 5000 paces.<ref name="Apian Cosmographie">Template:Cite book</ref> The common Dutch mile was preferred by mariners, equating with 15 to one degree of latitude or one degree of longitude on the equator. This was originally based upon Ptolemy's underestimate of the Earth's circumference. The ratio of 15 Dutch miles to a degree remained fixed while the length of the mile was changed as with improved calculations of the circumference of the Earth. In 1617, Willebrord Snellius calculated a degree of the circumference of the Earth at 28,500 {{#invoke:Lang|lang}} (within 3.5% of the actual value), which resulted in a Dutch mile of 1900 rods.<ref name="Metius">Template:Cite book</ref> By the mid-seventeenth century, map scales assigned 2000 rods to the common Dutch mile, which equalled around 7,535 m (reducing the discrepancy with latitude measurement to less than 2%). The metric system was introduced in the Netherlands in 1816, and the metric mile became a synonym for the kilometre, being exactly 1,000 m. Since 1870, the term {{#invoke:Lang|lang}} was replaced by the equivalent {{#invoke:Lang|lang}}. Today, the word {{#invoke:Lang|lang}} is no longer used, except as part of certain proverbs and compound terms like {{#invoke:Lang|lang}} ("miles away").

German

File:Wegmasse1.png

Various historic miles and leagues from an 1848 German textbook, given in feet, metres, and fractions of a "degree of meridian"

The German mile ({{#invoke:Lang|lang}}) was 24,000 German feet. The standardised Austrian mile used in southern Germany and the Austrian Empire was 7.586 km; the Prussian mile used in northern Germany was 7.5325 km. The Germans also used a longer version of the geographical mile.

Breslau

Template:Anchor The Breslau mile, used in Breslau, and from 1630 officially in all of Silesia, equal to 11,250 ells, or about 6,700 meters. The mile equaled the distance from the Piaskowa Gate all the way to Psie Pole (Hundsfeld). By rolling a circle with a radius of 5 ells through Piaskowa Island, Ostrów Tumski and suburban tracts, passing eight bridges on the way, the standard Breslau mile was determined.<ref>Template:Cite book</ref><ref>Template:Cite book</ref>

Saxon

The Saxon post mile ({{#invoke:Lang|lang}} or {{#invoke:Lang|lang}}, introduced on occasion of a survey of the Saxon roads in the 1700s, corresponded to 2,000 Dresden rods, equivalent to 9.062 kilometres.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Hungarian

Template:Anchor The Hungarian mile ({{#invoke:Lang|lang}} or {{#invoke:Lang|lang}}) varied from 8.3790 km to 8.9374 km before being standardised as 8.3536 km.

Portuguese

Template:Anchor The Portuguese mile ({{#invoke:Lang|lang}}) used in Portugal and Brazil was 2.0873 km prior to metrication.Template:Sfnp

Russian

Template:Anchor The Russian mile ({{#invoke:Lang|lang}} or {{#invoke:Lang|lang}}, {{#invoke:Lang|lang}}) was 7.468 km, divided into 7 versts.

Croatian

Template:Anchor Template:Anchor The Croatian mile ({{#invoke:Lang|lang}}), first devised by the Jesuit Stjepan Glavač on a 1673 map, is the length of an arc of the equator subtended by Template:Sfrac° or 11.13 km exactly.<ref>Template:In lang "Centuries of Natural Science in Croatia : Theory and Application" Template:Webarchive. Kartografija i putopisi.</ref><ref>Template:Cite journal</ref> The previous Croatian mile, now known as the "ban mile" ({{#invoke:Lang|lang}}), had been the Austrian mile given above.<ref>Template:Cite magazine</ref>

Ottoman

The Ottoman mile was 1,894.35 m, which was equal to 5,000 Ottoman foot. After 1933, the Ottoman mile was replaced with the modern Turkish mile (1,853.181 m).

Japanese

The CJK Compatibility Unicode block contains square-format versions of Japanese names for measurement units as written in katakana script. Among them, there is Template:Unichar, after {{#invoke:Lang|lang}} Template:Transliteration.

International

The international mile is precisely equal to Template:Val (or Template:Sfrac km as a fraction).Template:Refn It was established as part of the 1959 international yard and pound agreement reached by the United States, the United Kingdom, Canada, Australia, New Zealand, and the Union of South Africa,Template:Sfnp which resolved small but measurable differences that had arisen from separate physical standards each country had maintained for the yard.Template:Sfnp As with the earlier statute mile, it continues to comprise 1,760 yards or 5,280 feet.

The difference from the previous standards was 2 ppm, or about 3.2 millimetres (Template:Frac inch) per mile. The US standard was slightly longer and the old Imperial standards had been slightly shorter than the international mile. When the international mile was introduced in English-speaking countries, the basic geodetic datum in America was the North American Datum of 1927 (NAD27). This had been constructed by triangulation based on the definition of the foot in the Mendenhall Order of 1893, with 1 foot = Template:Sfrac (≈0.304800609601) metres and the definition was retained for data derived from NAD27, but renamed the US survey foot to distinguish it from the international foot.Template:Sfnp<ref group="n">When reading the document it helps to bear in mind that 999,998 = 3,937 × 254.</ref> Thus a survey mile = Template:Sfrac × 5280 (≈1609.347218694) metres. An international mile = 1609.344 / (Template:Sfrac × 5280) (=0.999998) survey miles.

The exact length of the land mile varied slightly among English-speaking countries until the international yard and pound agreement in 1959 established the yard as exactly 0.9144 metres, giving a mile of exactly 1,609.344 metres. The US adopted this international mile for most purposes, but retained the pre-1959 mile for some land-survey data, terming it the U. S. survey mile. In the United States, statute mile normally refers to the survey mile,<ref>Convert mile [statute] to mile [statute, US] Template:Webarchive "1 metre is equal to Template:Val mile [statute], or Template:Val mile [statute, US]. ... The U.S. statute mile (or survey mile) is defined by the survey foot. This is different from the international statute mile, which is defined as exactly 1609.344 metres. The U.S. statute mile is defined as 5,280 U.S. survey feet, which is around Template:Val metres."</ref> about 3.219 mm (Template:Frac inch) longer than the international mile (the international mile is exactly 0.0002% less than the US survey mile).

While many countries abandoned the mile when switching to the metric system, the international mile continues to be used in some countries, such as Liberia, Myanmar,<ref>File:Naypyitaw Tollbooth.jpg</ref> the United Kingdom<ref>Template:Cite legislation UK</ref> and the United States.<ref>Maximum posted speed limits Template:Webarchive (US) IIHS. Retrieved 14 September 2011</ref> It is also used in a number of territories with less than a million inhabitants, most of which are UK or US territories, or have close historical ties with the UK or US: American Samoa,<ref>Template:Cite news</ref> Bahamas,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Belize,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> British Virgin Islands,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Cayman Islands,<ref name="compasscayman.com">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Dominica,<ref name="compasscayman.com"/> Falkland Islands,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Grenada,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Guam,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The N. Mariana Islands,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Samoa,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> St. Lucia,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> St. Vincent & The Grenadines,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> St. Helena,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> St. Kitts & Nevis,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> the Turks & Caicos Islands,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and the US Virgin Islands.<ref>Template:Cite news</ref> The mile is even encountered in Canada, though this is predominantly in rail transport and horse racing, as the roadways have been metricated since 1977.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}Template:PbAct current to 18 January 2012. Canadian units (5) The Canadian units of measurement are as set out and defined in Schedule II, and the symbols and abbreviations therefor are as added pursuant to subparagraph 6(1)(b)(ii).</ref><ref>Weights and Measures Act Template:Webarchive</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}Template:PbFebruary 2012, Rail Report – 2010 – Report Number R10E0096. Other Factual Information (See Figure 1). 2. Assignment 602 travelled approximately 12 car lengths into track VC-64 and at a speed of 9 mph struck a stationary cut of 46 empty cars (with the air brakes applied) that had been placed in the track about Template:Frac hours earlier. Canadian railways have not been metricated and therefore continue to measure trackage in miles and speed in miles per hour.</ref><ref>Hastings Racecourse Fact Book Template:Webarchive Like Canadian railways, Canadian race tracks have not been metricated and continue to measure distance in miles, furlongs, and yards (see page 18 of the fact book).</ref> Ireland gradually replaced miles with kilometres, including in speed measurements; the process was completed in 2005.

US survey

Template:For The US survey mile is 5,280 US survey feet, or 1,609.347 metres and 0.30480061 metres respectively.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }} (links to a Microsoft Word document)</ref> Both are very slightly longer than the international mile and international foot. In the United States, the term statute mile formally refers to the survey mile,Template:Sfnp but for most purposes, the difference of less than Template:Convert between the survey mile and the international mile (1609.344 metres exactly) is insignificant—one international mile is Template:Val US survey miles—so statute mile can be used for either. But in some cases, such as in the US State Plane Coordinate Systems (SPCSs), which can stretch over hundreds of miles,<ref name="NGS-FAQ">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> the accumulated difference can be significant, so it is important to note that the reference is to the US survey mile.

The United States redefined its yard in 1893, and this resulted in US and Imperial measures of distance having very slightly different lengths.

The North American Datum of 1983 (NAD83), which replaced the NAD27, is defined in metres. State Plane Coordinate Systems were then updated, but the National Geodetic Survey left individual states to decide which (if any) definition of the foot they would use. All State Plane Coordinate Systems are defined in metres, and 42 of the 50 states only use the metre-based State Plane Coordinate Systems. However, eight states also have State Plane Coordinate Systems defined in feet, seven of them in US survey feet and one in international feet.<ref name="NGS-FAQ" />

State legislation in the US is important for determining which conversion factor from the metric datum is to be used for land surveying and real estate transactions, even though the difference (2 ppm) is hardly significant, given the precision of normal surveying measurements over short distances (usually much less than a mile). Twenty-four states have legislated that surveying measures be based on the US survey foot, eight have legislated that they be based on the international foot, and eighteen have not specified which conversion factor to use.<ref name="NGS-FAQ" />

SPCS 83 legislation refers to state legislation that has been passed or updated using the newer 1983 NAD data. Most states have done so. Two states, Alaska and Missouri, and two jurisdictions, Guam and Puerto Rico, do not specify which foot to use.<ref name="NGS-FAQ" /> Two states, Alabama and Hawaii, and four jurisdictions, Washington, DC, US Virgin Islands, American Samoa and Northern Mariana Islands, do not have SPCS 83 legislation.<ref name="NGS-FAQ" />

In October 2019, US National Geodetic Survey and National Institute of Standards and Technology announced their joint intent to retire the US survey foot and US survey mile, as permitted by their 1959 decision, with effect on January 1, 2023.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Nautical

File:RechtwKugeldreieck.svg

On the utility of the nautical mile.
Each circle shown is a great circle—the analogue of a line in spherical trigonometry—and hence the shortest path connecting two points on the globular surface. Meridians are great circles that pass through the poles.

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The nautical mile was originally defined as one minute of arc along a meridian of the Earth.Template:Sfnp Navigators use dividers to step off the distance between two points on the navigational chart, then place the open dividers against the minutes-of-latitude scale at the edge of the chart, and read off the distance in nautical miles.Template:Sfnp The Earth is not perfectly spherical but an oblate spheroid, so the length of a minute of latitude increases by 1% from the equator to the poles, as seen for example in the WGS84 ellipsoid, with Template:Convert at the equator, Template:Convert at the poles and average Template:Convert.

Since 1929 the international nautical mile is defined by the First International Extraordinary Hydrographic Conference in Monaco as exactly 1,852 metres (which is Template:Convert or Template:Convert).<ref>Template:SIBrochure8th.</ref> In the United States, the nautical mile was defined in the 19th century as Template:Convert, whereas in the United Kingdom, the Admiralty nautical mile was defined as Template:Convert and was about one minute of latitude in the latitudes of the south of the UK. Other nations had different definitions of the nautical mile.

Related units

The nautical mile per hour is known as the knot. Nautical miles and knots are almost universally used for aeronautical and maritime navigation, because of their relationship with degrees and minutes of latitude and the convenience of using the latitude scale on a map for distance measuring.

The data mile is used in radar-related subjects and is equal to 6,000 feet (1.8288 kilometres).Template:Sfnp The radar mile is a unit of time (in the same way that the light year is a unit of distance), equal to the time required for a radar pulse to travel a distance of two miles (one mile each way). Thus, the radar statute mile is 10.8 μs and the radar nautical mile is 12.4 μs.Template:Sfnp

Geographical

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The geographical mile is based upon the length of a meridian of latitude. The German geographical mile ({{#invoke:Lang|lang}}) was previously Template:Frac° of latitude (7.4127 km).Template:Sfnp

Metric

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The informal term "metric mile" is used in some countries, in sports such as track and field athletics and speed skating, to denote a distance of Template:Convert. The 1500 meters is the premier middle distance running event in Olympic sports. In United States high-school competition, the term is sometimes used for a race of Template:Convert.Template:Sfnp

Scandinavian

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The Scandinavian mile ({{#invoke:Lang|lang}}) remains in common use in Norway and Sweden, where it has meant precisely 10 km since metrication in 1889.Template:Sfnp It is used in informal situations and in measurements of fuel consumption, which are often given as litres per {{#invoke:Lang|lang}}. In formal situations (such as official road signs) only kilometres are given.

The Swedish mile was standardised as 36,000 Swedish feet or Template:Convert in 1649; before that it varied by province from about 6 to 14.485 km.Template:Sfnp

Before metrication, the Norwegian mile was Template:Convert.

The traditional Finnish {{#invoke:Lang|lang}} was translated as Template:Langx and also set equal to 10 km during metrication in 1887, but is much less commonly used.

Comparison table

A comparison of the different lengths for a "mile", in different countries and at different times in history, is given in the table below. Leagues are also included in this list because, in terms of length, they fall in between the short West European miles and the long North, Central and Eastern European miles.

Length (m)	Name	Country used	From	To	Definition	Remarks
Template:0500	lǐ	mainland China	1984	today	1,500 chi	In Chinese, this unit and the imperial mile are written using the same word (里), with a qualifier to distinguish between systems if needed
Template:0960–1,152	Talmudic mil	Land of Israel/Canaan		today	2,000 amot (cubits)	Biblical and Talmudic units of measurement
Template:01,480	mille passus, milliarium	Roman Empire				Ancient Roman units of measurement
Template:01,486.6	lang}}. Verlag von J. Engelhorn, Stuttgart, 1863, p. 332</ref>	Sicily
Template:01,524	London mile	England
Template:01,609.3426	(statute) mile	England/UK	1592	1959	1,760 yards	Over the course of time, the length of a yard changed several times and consequently so did the English, and from 1824, the imperial mile. The statute mile was introduced in 1592 during the reign of Queen Elizabeth I
Template:01,609.344	mile	some English speaking countriesTemplate:Citation needed	1959	today	1,760 yards	On 1 July 1959, the imperial mile was standardized to an exact length in metres. This figure corresponds to 5280 feet at 25.4 millimeters per inch.
Template:01,609.3472	(statute) mile	United States	1893	2022	1,760 yards	From 1959 also called the US Survey Mile. From then, its only utility has been land survey, before it was the standard mile. From 1893, its exact length in metres was: Template:Sfrac × 1760
Template:01,807	Scots mile	Scotland		1685	5,920 feet
Template:01,820		Italy
Template:01,852	nautical mile	international		today	approx. 1 minute of arc	Measured at a circumference of 40,000 km. Abbreviation: NM, nm
Template:01,852.3	(for comparison)				1 meridian minute
Template:01,853.181	nautical mile	Turkey
Template:01,855.4	(for comparison)				1 equatorial minute	Although the NM was defined on the basis of the minute, it varies from the equatorial minute, because at that time the circumference of the equator could only be estimated at 40,000 km.
Template:02,065		Portugal
Template:02,220	Gallo-Roman league	Gallo-Roman culture			1.5 miles	Under the reign of Emperor Septimius Severus, this replaced the Roman mile as the official unit of distance in the Gallic and Germanic provinces, although there were regional and temporal variations.<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>
Template:02,470		Sardinia, Piemont
Template:02,622		Scotland
Template:02,880		Ireland
Template:03,780		Flanders
Template:03,898	French lieue (post league)	France			2,000 "body lengths"
Template:03,927	Ri	Japan			12,960 shaku
Template:04,000	general or metric league
Template:04,000	legue	Guatemala
Template:04,190	legue	Mexico<ref name="BI">Template:Citation</ref>			= 2,500 tresas = 5,000 varas
Template:04,444.8	landleuge				Template:Frac° of a circle of longitude
Template:04,452.2	lieue commune	France				Units of measurement in France before the French Revolution
Template:04,513	legue	Paraguay
Template:04,513	legua	Chile,<ref name="BI" /> (Guatemala, Haiti)			= 36 cuadros = 5,400 varas
Template:04,808		Switzerland
Template:04,828	English land league	England			3 miles
Template:04,800 Template:04,900	Germanic rasta, also doppelleuge (double league)
Template:05,000	légua nova	Portugal<ref name="BI" />
Template:05,196	legua	Bolivia<ref name="BI" />			= 40 ladres
Template:05,152	legua Argentina	Argentina, Buenos Aires<ref name="BI" />			= 6,000 varas
Template:05,154	legue	Uruguay
Template:05,200	Bolivian legua	Bolivia
Template:05,370	legue	Venezuela
Template:05,500	Portuguese legua	Portugal
Template:05,510	legue	Ecuador
Template:05,510	Ecuadorian legua	Ecuador
Template:05,532.5	Landleuge (state league)	Prussia				Obsolete German units of measurement
Template:05,540	legue	Honduras
Template:05,556	Seeleuge (nautical league)				Template:Frac° of a circle of longitude 3 nautical miles
Template:05,570	legua	Spain and Chile				Spanish customary units
Template:05,572	legua	Colombia<ref name="BI" />			= 3 Millas
Template:05,572.7	legue	Peru<ref name="BI" />			= 20,000 feet
Template:05,572.7	legua Antigua old league	Spain<ref name="BI" />			= 3 millas = 15,000 feet
Template:05,590	légua	Brazil<ref name="BI" />			= 5,000 varas = 2,500 bracas
Template:05,600	Brazilian legua	Brazil
Template:05,685	Fersah (Turkish league)	Ottoman Empire		1933	4 Turkish miles	lang}}
Template:05,840<ref>IKAR-AltkartendatenbankTemplate:Dead link der Staatsbibliothek zu Berlin, Kartenabteilung.</ref>	Dutch mile	Holland
Template:06,170	milltir	Wales		13thC	9,000 camau ( = 27,000 troedfeddi = 243,000 inches)	Eclipsed by the conquest of Wales by Edward I
Template:06,197	légua antiga	Portugal<ref name="BI" />			= 3 milhas = 24 estadios
Template:06,240	Persian legue	Persia
Template:06,277		Luxembourg
Template:06,280		Belgium
Template:06,687.24	legua nueva new league, since 1766	Spain<ref name="BI" />			= 8,000 varas
Template:06,700	Breslau mile	Silesia	1630	1872		lang}} in Polish
Template:06,797	lang}} (state survey mile)	Saxony				Obsolete German units of measurement
Template:07,400		Netherlands
Template:07,409	(for comparison)				4 meridian minutes
Template:07,419.2		Kingdom of Hanover				Obsolete German units of measurement
Template:07,419.4		Duchy of Brunswick				Obsolete German units of measurement
Template:07,420.4 Template:07,414.9		Bavaria				Obsolete German units of measurement
Template:07,420.439	geographic mile				Template:Frac equatorial grads {{ safesubst:#invoke:Unsubst	$B= Template:Fix }} ||
Template:07,421.6	(for comparison)				4 equatorial minutes
Template:07,448.7		Württemberg				Obsolete German units of measurement
Template:07,450		Hohenzollern				Obsolete German units of measurement
Template:07,467.6		Russia			7 verst	Obsolete Russian units of measurement
Template:07,480		Bohemia
Template:07,500	kleine / neue Postmeile (small/new postal mile)	Saxony		1840		German Empire, North German Confederation, Grand Duchy of Hesse, Russia. Obsolete German units of measurement
Template:07,532.5	Land(es)meile (German state mile)	Denmark, Hamburg, Prussia				Primarily for Denmark defined by Ole Rømer. Obsolete German units of measurement
Template:07,585.9	Postmeile (post mile)	Austro-Hungary				Austrian units of measurement
Template:07,850	Milă	Romania
Template:08,534.31	Mila	Poland	1819			7146 meters before 1819, also equaled 7 verst<ref>Template:Cite book</ref>
Template:08,800		Schleswig-Holstein				Obsolete German units of measurement
Template:08,888.89		Baden				Obsolete German units of measurement
Template:09,062	mittlere Post- / Polizeimeile (middle post mile or police mile)	Saxony		1722		Obsolete German units of measurement
Template:09,206.3		Electorate of Hesse				Obsolete German units of measurement
Template:09,261.4	(for comparison)				5 meridian minutes
Template:09,277	(for comparison)				5 equatorial minutes
Template:09,323	alte Landmeile (old state mile)	Hanover		1836		Obsolete German units of measurement
Template:09,347	alte Landmeile (old state mile)	Hanover		1836		Obsolete German units of measurement
Template:09,869.6		Oldenburg
10,000	metric mile, Scandinavian mile	Norway, Sweden		today		Still commonly used today, e.g. for road distances; equates to the myriametre
10,044	große Meile (great mile)	Westphalia				Obsolete German units of measurement
10,670		Finland
10,688.54	mil	Sweden		1889		In normal speech, "mil" means a Scandinavian mile of 10 km.
11,113.7	(for comparison)				6 meridian minutes
11,132.4	(for comparison)				6 equatorial minutes
11,299	mil	Norway				was equivalent to 3,000 Rhenish rods.

Similar units:

• 1,066.8 m – verst, see also obsolete Russian units of measurement

Idioms

The mile is still used in a variety of idioms, even in English-speaking countries that have moved from the Imperial to the metric system (for example, Australia, Canada, or New Zealand). These idioms include:

• A country mile is used colloquially to denote a very long distance
• "A miss is as good as a mile" (failure by a narrow margin is no better than any other failure)
• "Give him an inch and he'll take a mile" – a corruption of "Give him an inch and he'll take an ell"<ref>Concise Oxford English Dictionary (5th edition; 1964). Oxford University Press.</ref><ref name="Heywood1562">Template:Cite book</ref> (the person in question will become greedy if shown generosity)
• "Missed by a mile" (missed by a wide margin)
• "Go a mile a minute" (move very quickly)
• "Talk a mile a minute" (speak at a rapid rate)
• "To go the extra mile" (to put in extra effort)
• "Miles away" (lost in thought, or daydreaming)
• "Milestone" (an event indicating significant progress)
• Glasgow's miles better, a touristic campaign.

References

Sources

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Further reading

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