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Mile
A milestone in the City of Westminster showing the distance from Kensington Road to Hounslow and Hyde Park Corner in miles
General information
Unit systemBritish imperial/US customary
Unit oflength
Symbolmi. or mi, (rarely) m
Conversions
1 mi. or mi in ...... is equal to ...
   SI units   1609.344 m
   imperial/US units   
   US survey mile   0.999998 survey mile
   nautical units   ≈ 0.86898 nmi[n 1]

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 the yard was formally redefined with respect to SI units as 0.9144 metres, making the mile exactly 1609.344 metres (1.609344 kilometres). For everyday use, five miles equates roughly to eight kilometres.

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 1.48 km), such as the nautical mile (now 1.852 km exactly), the Italian mile (roughly 1.852 km), and the Chinese mile (now 500 m exactly). The Romans divided their mile into 5,000 pedes (lit. 'feet'), but the greater importance of furlongs in the Elizabethan-era England meant that the statute mile was made equivalent to 8 furlongs or 5,280 feet 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 (⁠6336/3937⁠ km) 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

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The modern English word mile derives from Middle English myle and Old English mīl, which was cognate with all other Germanic terms for miles. These derived from the nominal ellipsis form of mīlle passus 'mile' or mīlia passuum 'miles', the Roman mile of one thousand paces.[1]

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.[2] 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 1,760 yards. Under American law, however, statute mile refers to the US survey mile.[3] 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

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The mile has been variously abbreviated in English—with and without a trailing period—as "mi", "M", "ml", and "m".[4] The American National Institute of Standards and Technology now uses and recommends "mi" to avoid confusion with the SI metre (m) and millilitre (ml).[5] 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.[6] The BBC style holds that "there is no acceptable abbreviation for 'miles'" and so it should be spelled out when used in describing areas.[7]

Historical

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

Roman

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Main articles: Ancient Roman units of measurement and Byzantine units of measurement

The Roman mile (mille passus, lit. "thousand paces"; abbr. m.p.; also milia passuum[n 2] and mille) 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.[9] The distance was indirectly standardised by Agrippa's establishment of a standard Roman foot (Agrippa's own) in 29 BC,[10] and the definition of a pace as 5 (Roman) feet.[citation needed] An Imperial Roman mile thus denoted 5,000 Roman feet. Surveyors and specialised equipment such as the decempeda and dioptra then spread its use.[11]

In modern times, Agrippa's Imperial Roman mile was empirically estimated to have been about 1,618 yards (1,479 m; 4,854 ft; 0.919 mi) in length, slightly less than the 1,760 yards (1,609 m; 5,280 ft) of the modern international mile.[12]

In Hellenic areas of the Empire, the Roman mile (Ancient Greek: μίλιον, mílion) was used beside the native Greek units as equivalent to 8 stadia of 600 Greek feet. The mílion 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.[13] 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.[14]

Ptolemaic mile

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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 earth's circumference, equivalent to 1:60 of a degree of longitude, or 1:21,600 of the circumference.[15] While his estimate of the circumference of the earth, and therefore the derived length of a stade, and a mile, from third party observations, principally offered in non-normalised stadion (600 Greek feet), Egyptian schoinos, and Persian parasang were erroneous.[clarification needed] Ptolomy's assumptions of a customary stade to be ⁠1/8⁠ of a Roman mile, ⁠1/30⁠ of a schoinos or parasang, ⁠1/500⁠ of an arc-minute, or ~185 metres,[16][17] his Geographical mile, is the basis of the current nautical mile, and was adopted by medieval Arab and European cartographers.[18][19]

Arabic

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Main article: Arabic mile

The Arabic mile (الميل, al-mīl), 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.

Breslau

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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.[20][21]

Croatian

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The Croatian mile (hrvatska milja), first devised by the Jesuit Stjepan Glavač on a 1673 map, is the length of an arc of the equator subtended by ⁠1/10⁠° or 11.13 km exactly.[22][23] The previous Croatian mile, now known as the "ban mile" (banska milja), had been the Austrian mile given above.[24]

Danish

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Main article: Danish units of measurement

Following its standardisation by Ole Rømer in the late 17th century, the Danish mile (mil) was precisely equal to the Prussian mile and likewise divided into 24,000 feet.[25] These were sometimes treated as equivalent to 7.5 km. Earlier values had varied: the Sjællandske miil, for instance, had been 11.13 km.

Dutch

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Scalebar on a Mercator map
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 (mijl) 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 (kleine), medium (middelbaar/gemeen), and large (groote). The Dutch kleine mile had the historical definition of one hour's walking (uur gaans), 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.[26] 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 Rijnlantsche Roeden (within 3.5% of the actual value), which resulted in a Dutch mile of 1900 rods.[27] 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 mijl was replaced by the equivalent kilometer. Today, the word mijl is no longer used, except as part of certain proverbs and compound terms like mijlenver ('miles away').

English

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Main article: English units of measurement

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).[28][29] The old English mile varied over time and location within England.[29] The old English mile has also been defined as 79,200 or 79,320 inches (1.25 or 1.2519 statute miles).[30] 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.[31]

The origins of English units are "extremely vague and uncertain",[32] but seem to have been a combination of the Roman system with native and Germanic systems both derived from multiples of the barleycorn.[n 3] 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;[33][32] 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.[32] Following the issuance of Magna Carta in 1215, the barons of Parliament directed John and his son to keep the king's standard measure (Mensura Domini Regis) and weight at the Exchequer,[32] 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.[35]

Arnold's c. 1500 Customs of London recorded a mile shorter than previous ones, coming to 0.947 international miles (5,000 feet) or 1.524 km.[31]

English statute

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"Statute mile" redirects here. For the current statute mile in the United Kingdom, see § International. For the statute mile in the United States, see § US survey.

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.[36] Owing to the importance of the surveyor's rod in deeds and surveying undertaken under Henry VIII,[37] decreasing the length of the rod by 1⁄11 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.[38] The applicable passage of the statute reads: "A Mile shall contain eight Furlongs, every Furlong forty Poles,[n 4] and every Pole shall contain sixteen Foot and an half."[40] The statute mile therefore contained 5,280 feet or 1,760 yards.[31] 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 1 : 1.23[41] and his map of Dorset had three scales with a ratio of 1 : 1.23 : 1.41.[42] 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.

German

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

The German mile (Meile) 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.

Hungarian

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The Hungarian mile (mérföld or magyar mérföld) varied from 8.3790 km to 8.9374 km before being standardised as 8.3536 km.

Irish

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Main article: Irish mile
Milestone on Mountbellew Bridge, erected c. 1760. Distances are given in Irish miles.

The Irish mile (míle or míle Gaelach) measured 2,240 yards: approximately 1.27 statute miles or 2.048 kilometres.[43][44] 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 7 yards (6.4 m) as opposed to the English rod of 5.5 yards (5.0 m).[44]

Italian

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Main article: Italian units of measurement

The Italian mile (miglio, pl. miglia) was traditionally considered a direct continuation of the Roman mile, equal to 1000 paces,[45] although its actual value over time or between regions could vary greatly.[46] It was often used in international contexts from the Middle Ages into the 17th century[45] and is thus also known as the "geographical mile",[47] although the geographical mile is now a separate standard unit.

Japanese

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The CJK Compatibility Unicode block contains square-format versions of Japanese names for measurement units as written in katakana script. Among them, there is U+3344 ㍄ SQUARE MAIRU, after マイル mairu.

Ottoman

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Main article: Ottoman units of measurement

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).

Portuguese

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The Portuguese mile (milha) used in Portugal and Brazil was 2.0873 km prior to metrication.[48]

Russian

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The Russian mile (миля or русская миля, russkaya milya) was 7.468 km, divided into 7 versts.

Saxon

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The Saxon post mile (kursächsische Postmeile or Polizeimeile, introduced on occasion of a survey of the Saxon roads in the 1700s, corresponded to 2,000 Dresden rods, equivalent to 9.062 kilometres.[49]

Old Scandinavian

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Main articles: Scandinavian mile and Scandinavian nautical mile
See also: Danish units of measurement, Norwegian units of measurement, and Swedish units of measurement

The old Scandinavian miles (Norse: mil, [miːl], Finnish: peninkulma) were a number of measurements of length used in Scandinavia prior to the adoption of the modern "Scandinavian metric mile" (10 km) in the late 19th century.

Before the Renaissance, there were various regional miles in Scandinavia. In Sweden, the regional miles were eventually divided after province, so called landskapsmil (roughly "county miles").[50][51][52] Some noteworthy Swedish county miles are:

While Denmark eventually adopted the Prussian mile (see § Danish mile), the Swedish kept their indigenous miles. In 1649 the Swedish government made the Uppland mile the de facto Swedish mile, or "unit mile" (enhetsmil), for all of Sweden, also called the "land mile" or "long mile". In Finland, then part of Sweden, their measurement peninkulma (which is translated as "mile") then became equivelant to the Swedish "unit mile", which later carried over when Finland seceded to the Russian Empire in 1809. When Norway became part of Sweden in 1814, forming the Union between Sweden and Norway, the Swedish standard for defining a "unit mile", 36,000 feet, was introduced to Norway, which, due to the Norwegian foot being slightly longer than the Swedish foot, then became slightly longer than in Sweden, making the "unit mile" 11.298 kilometres (7.020 miles) in Norway.

Upon metrification, Finland, Norway, and Sweden, decided to redefine their miles as 10 kilometres (6.2 mi), since they were all based on the old Swedish "unit mile", already close to the measurent. The modern Scandinavian (metric) mile is still a unit of length common in Norway and Sweden, to a lesser extent in Finland, but not Denmark.

The Scandinavians also had their own "nautical mile", called "sea mile" (Danish: sømil, Norwegian: sjømil, Swedish: sjömil), or the equivelant "sea-peninkulma" in Finnish (Finnish: meripeninkulma), equivelant to the German geographical mile (1⁄15 degrees of latitude), around 7,413 m (24,321 ft); later, during metrification, standardized as 7,420 m (24,340 ft).

Scots

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Main article: Scottish units of measurement
Edinburgh's "Royal Mile"—running from the castle to Holyrood Abbey—is roughly a Scots mile long.[53]

The Scots mile was longer than the English mile,[54] 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).[55] 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,[56] again by the 1707 Treaty of Union with England,[57] and finally by the Weights and Measures Act 1824.[54] It had continued in use as a customary unit through the 18th century but had become obsolete by its final abolition.

Welsh

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Main article: Welsh units of measurement

The Welsh mile (milltir or milldir) was 3 statute miles and 1,470 yards long (6.17 km). It comprised 9,000 paces (cam), each of 3 Welsh feet (troedfedd) of 9 inches (modfeddi).[58] (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.[59] Along with other Welsh units, it was discontinued following the conquest of Wales by Edward I of England in the 13th century.

International

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Main article: International System of Units

The international mile is precisely equal to 1.609344 km (or ⁠25146/15625⁠ km as a fraction).[61] 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,[62] which resolved small but measurable differences that had arisen from separate physical standards each country had maintained for the yard.[63] 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 (1⁄8 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 = ⁠1200/3937⁠ (≈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.[64][n 5] Thus a survey mile = ⁠1200/3937⁠ × 5280 (≈1609.347218694) metres. An international mile = 1609.344 / (⁠1200/3937⁠ × 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,[65] about 3.219 mm (1⁄8 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,[66] the United Kingdom[67] and the United States.[68] 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,[69] Bahamas,[70] Belize,[71] British Virgin Islands,[72] Cayman Islands,[73] Dominica,[73] Falkland Islands,[74] Grenada,[75] Guam,[76] The N. Mariana Islands,[77] Samoa,[78] St. Lucia,[79] St. Vincent & The Grenadines,[80] St. Helena,[81] St. Kitts & Nevis,[82] the Turks & Caicos Islands,[83] and the US Virgin Islands.[84] 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.[85][86][87][88] Ireland gradually replaced miles with kilometres, including in speed measurements; the process was completed in 2005.

US survey

[edit]
For the detailed calculations of international miles to survey miles and feet (above), see § International.

The US survey mile is 5,280 US survey feet, or 1,609.347 metres and 0.30480061 metres respectively.[89] 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,[3] but for most purposes, the difference of less than 1⁄8 inch (3.2 mm) between the survey mile and the international mile (1609.344 metres exactly) is insignificant—one international mile is 0.999998 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,[90] 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.[90]

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.[90]

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.[90] 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.[90]

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.[91][92][93]

Nautical

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International nautical

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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.
Main article: Nautical mile

The nautical mile (historically also (sea mile) was originally defined as one minute of arc along a meridian of the Earth.[94] 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.[95] 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 1,843 metres (6,046 ft) at the equator, 1,862 metres (6,108 ft) at the poles and average 1,852 metres (6,076 ft).

Since 1929 the international nautical mile is defined by the First International Extraordinary Hydrographic Conference in Monaco as exactly 1,852 metres (which is 1.151 miles or 6,076.12 feet).[96] In the United States, the nautical mile was defined in the 19th century as 6,080.2 feet (1,853.24 m), whereas in the United Kingdom, the Admiralty nautical mile was defined as 6,080 feet (1,853.18 m) 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.

[edit]

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).[97] 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.[98]

Scandinavian nautical

[edit]
Main article: Scandinavian nautical mile

Scandinavians used their own version of the "nautical mile" up to the beginning of the 20th century (with continued regional use), indigenously known as a sea mile (Danish: sømil, Norwegian: sjømil, Swedish: sjömil), or the equivelant "sea-peninkulma" in Finnish (Finnish: meripeninkulma). It was equal to a "geographical mile", defined as 1⁄15 of an equatorial degree (1⁄360° of longitude),[99] equivalent to approximately four modern nautical miles or "medium meridian minutes" (4 × 1,852 m) – a nautical mile is approximately one sixtieth of a degree along a meridian (1/60 meridian degree).

During metrification in 1875, this brought it down to about 7,420 m (24,340 ft) from its former equivalence of 3950 fathoms (Bokmål: favn, Swedish: famn) or about 7,435 m (24,393 ft).

Geographical

[edit]
Main article: Geographical mile

The geographical mile is based upon the length of a meridian of latitude. The German geographical mile (geographische Meile) was previously 1⁄15° of latitude (7.4127 km),[100] and was used as the basis for the Scandinavian nautical mile.

Metric

[edit]
Main article: Metric mile

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 1,500 metres (0.932 miles). 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 1,600 metres (0.994 miles).[101]

Metric mile has also been used to denote other metric measurements under the name mile, such as the Scandinavian mile (Swedish: metrisk mil),[102] and previously also the kilometre, in Dutch.

Scandinavian metric

[edit]
Main article: Scandinavian mile

The Scandinavian metric mile (Norwegian and Swedish: mil, [miːl]) refers to the modern Scandinavian mile, used in Norway and Sweden, to a lesser extent in Finland (Finnish: peninkulma), but not in Denmark, which since metrication in the late 19th century is standardized as 10 km.[25] It is used in informal situations and in measurements of fuel consumption, which are often given as litres per mil. In formal situations (such as official road signs) only kilometres are given.

The Scandinavian metric mile is based of the old Swedish "unit mile" (Swedish: enhetsmil), which was standardised as 36,000 Swedish feet or 10.6884 kilometres (6.6415 miles) in 1649; before that, the mile varied by province from about 6–14.485 km (3.728–9.001 mi), also known as "county miles" (Swedish: landskapsmil).[25] In Finland, then part of Sweden, the traditional Finnish measurement peninkulma, or "Finnish mile" (Swedish: finsk mil), became redefined as equivelant to the Swedish "unit mile" Swedish: mil, which was then kept when Finland seceded to Russia in 1809. When Norway became part of Sweden in 1814, forming the Union between Sweden and Norway, the Swedish standard for defining a mile was introduced, which then became slightly longer in Norway than in Sweden, due to the Norwegian foot being slightly longer than the Swedish foot, making the "unit mile" 11.298 kilometres (7.020 miles) in Norway. Upon metrification, each country decided to redefine their mile to 10 kilometres.

Comparison table

[edit]

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
500 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
960–1,152 Talmudic mil Land of Israel/Canaan today 2,000 amot (cubits) Biblical and Talmudic units of measurement
1,480 mille passus, milliarium Roman Empire Ancient Roman units of measurement
1,486.6 miglio[103] Sicily
1,524 London mile England
1,609.3426 (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
1,609.344 mile some English speaking countries[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.
1,609.3472 (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: ⁠3600/3937⁠ × 1760
1,807 Scots mile Scotland 1685 5,920 feet
1,820 Italy
1,852 nautical mile international today approx. 1 minute of arc Measured at a circumference of 40,000 km. Abbreviation: NM, nm
1,852.3 (for comparison) 1 meridian minute
1,853.181 nautical mile Turkey
1,855.4 (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.
2,065 Portugal
2,220 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.[104]
2,470 Sardinia, Piemont
2,622 Scotland
2,880 Ireland
3,780 Flanders
3,898 French lieue (post league) France 2,000 "body lengths"
3,927 Ri Japan 12,960 shaku
4,000 general or metric league
4,000 legue Guatemala
4,190 legue Mexico[105] = 2,500 tresas = 5,000 varas
4,444.8 landleuge 1⁄25° of a circle of longitude
4,452.2 lieue commune France Units of measurement in France before the French Revolution
4,513 legue Paraguay
4,513 legua Chile,[105] (Guatemala, Haiti) = 36 cuadros = 5,400 varas
4,808 Switzerland
4,828 English land league England 3 miles
4,800
4,900		 Germanic rasta, also doppelleuge
(double league)
5,000 légua nova Portugal[105]
5,196 legua Bolivia[105] = 40 ladres
5,152 legua Argentina Argentina, Buenos Aires[105] = 6,000 varas
5,154 legue Uruguay
5,200 Bolivian legua Bolivia
5,370 legue Venezuela
5,500 Portuguese legua Portugal
5,510 legue Ecuador
5,510 Ecuadorian legua Ecuador
5,532.5 Landleuge
(state league)		 Prussia Obsolete German units of measurement
5,540 legue Honduras
5,556 Seeleuge (nautical league) 1⁄20° of a circle of longitude
3 nautical miles
5,570 legua Spain and Chile Spanish customary units
5,572 legua Colombia[105] = 3 Millas
5,572.7 legue Peru[105] = 20,000 feet
5,572.7 legua Antigua
old league		 Spain[105] = 3 millas = 15,000 feet
5,590 légua Brazil[105] = 5,000 varas = 2,500 bracas
5,600 Brazilian legua Brazil
5,685 Fersah (Turkish league) Ottoman Empire 1933 4 Turkish miles Derived from Persian parasang
5,840[106] Dutch mile Holland
6,170 milltir Wales 13thC 9,000 camau ( = 27,000 troedfeddi = 243,000 inches) Eclipsed by the conquest of Wales by Edward I
6,197 légua antiga Portugal[105] = 3 milhas = 24 estadios
6,240 Persian legue Persia
6,277 Luxembourg
6,280 Belgium
6,687.24 legua nueva
new league, since 1766		 Spain[105] = 8,000 varas
6,700 Breslau mile Silesia 1630 1872 Also known as mila wrocławska in Polish
6,797 Landvermessermeile
(state survey mile)		 Saxony Obsolete German units of measurement
7,400 Netherlands
7,409 (for comparison) 4 meridian minutes
7,419.2 Kingdom of Hanover Obsolete German units of measurement
7,419.4 Duchy of Brunswick Obsolete German units of measurement
7,420.4
7,414.9		 Bavaria Obsolete German units of measurement
7,420.439 geographic mile 1⁄15 equatorial grads [dubious – discuss]
7,421.6 (for comparison) 4 equatorial minutes
7,448.7 Württemberg Obsolete German units of measurement
7,450 Hohenzollern Obsolete German units of measurement
7,467.6 Russia 7 verst Obsolete Russian units of measurement
7,480 Bohemia
7,500 kleine / neue Postmeile
(small/new postal mile)		 Saxony 1840 German Empire, North German Confederation, Grand Duchy of Hesse, Russia. Obsolete German units of measurement
7,532.5 Land(es)meile
(German state mile)		 Denmark, Hamburg, Prussia Primarily for Denmark defined by Ole Rømer. Obsolete German units of measurement
7,585.9 Postmeile
(post mile)		 Austro-Hungary Austrian units of measurement
7,850 Milă Romania
8,534.31 Mila Poland 1819 7146 meters before 1819, also equaled 7 verst[107]
8,800 Schleswig-Holstein Obsolete German units of measurement
8,888.89 Baden Obsolete German units of measurement
9,062 mittlere Post- / Polizeimeile
(middle post mile or police mile)		 Saxony 1722 Obsolete German units of measurement
9,206.3 Electorate of Hesse Obsolete German units of measurement
9,261.4 (for comparison) 5 meridian minutes
9,277 (for comparison) 5 equatorial minutes
9,323 alte Landmeile
(old state mile)		 Hanover 1836 Obsolete German units of measurement
9,347 alte Landmeile
(old state mile)		 Hanover 1836 Obsolete German units of measurement
9,869.6 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:

Idioms

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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"[108][109] (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.

See also

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Notes

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References

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Further reading

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Revisions and contributorsEdit on WikipediaRead on Wikipedia

Mile

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from Grokipedia
The mile is a unit of length in the imperial and United States customary systems of measurement, equal to exactly 1,609.344 meters or 5,280 feet (or 1,760 yards). Primarily used in the United States, the United Kingdom, and a few other countries for everyday distance measurements, road signage, and athletics, it serves as a fundamental measure in non-metric contexts despite the global shift toward the metric system. The word "mile" derives from the Latin mille passus, meaning "thousand paces," tracing back to the ancient Roman mile, which approximated 1,000 double steps or about 1,480 meters. This unit evolved through medieval with varying lengths, but in 1593, the English standardized the statute mile as 8 furlongs or 5,280 feet to facilitate land surveying and trade. By the , slight discrepancies arose between national definitions, such as the U.S. survey mile (based on the survey foot) and the international mile, differing by about 3 millimeters. The U.S. survey foot was deprecated on December 31, 2022, after which the international mile is used exclusively in the United States. In 1959, an international agreement among the , the , , , , and precisely defined the yard as 0.9144 meters, thereby fixing the international mile at exactly 1,609.344 meters to harmonize customary units with the . Variants include the , standardized internationally at exactly 1,852 meters in and used in maritime and for its relation to Earth's latitude (one minute of arc, or 1/60th of a degree). Today, while the statute mile remains prominent in Anglo-American contexts, efforts toward have reduced its global use, though it persists in like track running (e.g., the mile race) and historical references.

Etymology and Terminology

Etymology

The English word "mile" derives from the Latin phrase mille passus, meaning "a thousand paces," which originally denoted a distance equivalent to 1,000 Roman paces in ancient systems. This term emerged in the Roman and administrative context, where a pace (passus) represented a double step taken by a marching , establishing the mile as a practical unit for road distances and travel. The word entered as mīl around the pre-1150 period, inherited through Proto-West Germanic mīljō and influenced by broader Germanic borrowings from Latin milia passuum ("thousands of paces"). By the era (circa 1100–1500), it evolved into myle or mile, reinforced by Norman influences including mile or mil, which itself stemmed directly from Latin mille ("thousand"). This linguistic adaptation solidified the term's usage in English, adapting the Roman concept to local contexts while preserving its core association with paced distances. Historical shifts in the term's meaning were closely tied to evolving pacing systems, from the standardized Roman military stride to varied medieval European practices where paces were recalibrated for regional needs, yet the "thousand paces" persisted as a foundational reference. A related etymological connection appears in the Latin milliarium, denoting Roman milestones that marked intervals of a thousand paces along roads, derived from mille ("thousand") combined with the suffix -arium for instruments or markers. This root underscores the mile's origins in imperial infrastructure, briefly linking to the Roman mile's pacing foundation without altering its broader linguistic trajectory.

Abbreviations and Symbols

The primary abbreviation for the mile in English is "mi" or "mi.", as established by standards bodies including the National Institute of Standards and Technology (NIST) and the (FAA). This notation serves both singular and plural forms, eliminating the need for additional indicators like "s" for multiples. Historically, "m" or "m." was commonly used for the mile in pre-metric English texts, but this changed with the adoption of the , where "m" became reserved for the meter. To avoid confusion, "mi" emerged as the modern standard, particularly following international agreements on in the mid-20th century. In scientific and engineering contexts, "mi" denotes the mile within imperial or customary systems, distinct from the metric "km" for kilometer, ensuring clarity in mixed-unit expressions such as conversion factors or . For instance, style guides like Microsoft's recommend "mi" for technical documentation to maintain precision across disciplines. In digital and print media, the abbreviation "mi" is typically rendered using standard , with no unique character dedicated solely to the mile; however, derived forms like square miles use superscript notation as "mi²" ( U+00B2 for the superscript 2). This plain-text approach facilitates consistent display across platforms, from technical papers to signage.

Historical Development

Roman Mile

The Roman mile, known as the mille passuum or milliare, was defined as 1,000 paces (passus), where each pace represented a double step equivalent to five Roman feet (pes). This structure made one Roman mile equal to 5,000 Roman feet in total. The Roman foot measured approximately 0.296 meters, yielding a total length for the mile of about 1,480 meters. This unit played a central role in the Roman road system, which spanned thousands of kilometers across the empire and was engineered for efficiency and durability. Distances along these roads were demarcated by milestones (milliaria), cylindrical stone columns erected at intervals of one mile, inscribed with the cumulative distance from a reference point—often —and details such as the road's endpoints or the who commissioned repairs. In military operations, the mile standardized legionary marches, allowing commanders to plan advances, establish camps, and maintain formation by having soldiers count paces collectively. During the Republican era, the mile exhibited some variations in application, particularly in provincial contexts like where local leagues occasionally supplemented Roman measures. The systematic use of milestones on public roads is attributed to around 123 BC, though isolated markers may have existed earlier. Standardization advanced in the late Republic through extensive road surveys ordered by , which informed imperial infrastructure, and was further refined under , who centralized the system with the Milliarium Aureum in the as the empire's notional zero point.

Ancient and Classical Variants

In the Ptolemaic period, which blended Egyptian and Greek metrological traditions, the mile emerged as a practical unit derived from subdivisions of the schoinos, an ancient Egyptian itinerant often set at 12,000 royal cubits or approximately 6,288 meters in the Ptolemaic system. This mile, used for land surveys and travel in and , approximated 1,520 meters, representing roughly a quarter of the schoinos and facilitating more granular distance reckoning in administrative and exploratory contexts. Its basis lay in local pacing and rope-based surveying techniques inherited from pharaonic , adapted under Ptolemaic rulers to align with Greek stadia measurements, where one schoinos equated to 40 stadia of about 38 meters each. The Arabic mile, or al-mil, developed within medieval Islamic geography as a key unit for mapping and trade, measuring around 1,973 meters and often defined as 4,000 black cubits of approximately 0.493 meters. Prominent scholars like incorporated it into calculations, using it to estimate degrees of along caravan routes from the to , where it supported precise itineraries in works like al-Biruni's Tahdid nihayat al-amakin. Unlike purely pacing-based systems, the al-mil drew on astronomical observations, such as measurements, to standardize distances across diverse terrains, emphasizing its role in the intellectual synthesis of Hellenistic, Persian, and Indian influences during the . As extensions of these classical traditions into later periods, the Croatian and Ottoman miles reflected ongoing adaptations in the and . The Croatian mile (hrvatska milja), introduced by Jesuit cartographer Stjepan Glavač in 1673, measured about 11,120 meters, calculated as one-tenth of a degree of latitude on the to aid regional mapping under Habsburg and Venetian influences. In contrast, the Ottoman mile (eski mil) stood at approximately 1,896 meters, equivalent to 5,000 Ottoman feet, and served and land administration, rooted in earlier Islamic and Byzantine pacing but refined through architectural evident in Sinan's structures. These variants highlighted differences in foundational methods: astronomical derivations for the Croatian mile versus hybrid pacing and systems for the Ottoman, diverging from shared pacing heritage with the Roman mile while prioritizing local and imperial needs.

Medieval English and Statute Mile

In medieval England, the mile evolved from Anglo-Saxon measurement traditions, where it was commonly defined as eight furlongs, a unit rooted in agricultural plowing practices and equivalent to approximately 1,760 yards or 5,280 feet. This configuration, influenced by earlier Germanic customs rather than direct Roman adoption, facilitated practical applications in travel, trade routes, and boundary demarcation across the landscape. Although the precise length varied regionally due to inconsistencies in local standards for the yard and foot, the eight-furlong mile provided a foundational linear measure for itinerant distances and early administrative records. Prior to formal , variations in the mile were evident, including an older form of approximately 5,000 feet or 1,667 yards, tied to customary pacing or local surveying needs for estates and commons. These discrepancies arose from the decentralized nature of Anglo-Saxon and early Norman governance, where local lords and shires maintained their own gauges, leading to disputes in commerce and legal proceedings. The mile played a crucial role in land measurement for feudal tenures, enabling the calculation of acreage through chains and perches, while also influencing taxation systems such as the hidage and carucage, which assessed obligations based on territorial extents. Indirectly, the of 1215 reinforced the need for uniform measures across the realm in Clause 35, mandating standardized units for commodities like corn and cloth that depended on consistent linear distances, thereby laying groundwork for broader metrological reform. The statute mile was definitively established by the English Parliament in 1593 through the Weights and Measures Act (35 Eliz. I, c. 6), which fixed the mile at exactly 1,760 yards or 5,280 feet to resolve lingering ambiguities and promote equitable trade. This legislation specified that "a mile shall contain eight furlongs, every furlong forty poles, and every pole shall contain sixteen foot and an half," aligning the unit with the established of 5.5 yards for greater precision in legal and economic contexts. By codifying the measure, the act enhanced its utility in taxation, such as for assessing road maintenance levies and customs duties on transported goods, marking a pivotal shift toward national uniformity in early modern .

Other European Historical Miles

In medieval and outside , numerous regional mile variants emerged, often rooted in Roman traditions but modified by local surveying practices, trade routes, and customary units like the ell, rod, or pace. These differences reflected the fragmented political landscape of the , Iberian kingdoms, and Eastern European states, where standardization was limited until the metric era. Among Celtic regions, the Welsh mile was approximately 6,760 yards (based on 9,000 Welsh feet), derived from a local system where the foot was shorter than the English equivalent to suit agrarian and territorial measurements. The Scots mile extended to 1,973 yards (or approximately 5,920 feet), incorporating eight Scots furlongs and used extensively in Scottish legal and travel documents until the Acts of Union in 1707 aligned it closer to English standards. The Irish mile reached 2,240 yards, based on eight Irish furlongs of 280 yards each, a unit tied to Gaelic land divisions and persisting in rural contexts into the . Continental variants showed greater diversity due to imperial and princely jurisdictions. The German mile averaged around 7,500 meters, though it fluctuated by territory—for instance, the in electoral was standardized at 7,500 meters in the for postal and road surveys. The Dutch mile measured about 4,000 meters, often defined as 15,000 rods and employed in and along the ' waterways. The Danish mile stood at approximately 7,532 meters (or 24,000 Danish feet), adopted across Scandinavian realms for military mapping and trade until in 1820. Further east and south, the Hungarian mile equated to 18,600 feet (roughly 5,670 meters), calibrated to local arshin and used in Habsburg-era cadastral surveys amid the kingdom's expansive plains. The mile was 2,088 meters, subdivided into 6,000 Portuguese feet and integral to colonial exploration and Iberian trade routes from the . The Russian mile measured 7,468 meters (equivalent to seven versts), a post-Petrine unit facilitating imperial expansion and railway planning in the 18th and 19th centuries. The Italian mile varied regionally but commonly reached 1,850 meters in Lombard and Tuscan contexts, evolving from Roman milia passuum for engineering and ecclesiastical estates. These units were profoundly shaped by local customs, such as the Saxon mile's alignment with Thuringian rod measures for and in central , or the Breslau mile's 6,700 meters in Silesian trade hubs, where it supported cross-border commerce under Prussian and Austrian influence until the . Such adaptations underscored the mile's role in regional economies, often prioritizing practical utility over uniformity.

Modern Standardization

International Mile

The international mile is a in the imperial and customary systems, defined as exactly 1,609.344 meters. This precise metric-based definition was established on July 1, 1959, through the International Yard and Pound Agreement, signed by national standards laboratories from , , , , the , and the to promote uniformity in scientific and technical measurements. The agreement fixed the yard at exactly 0.9144 meters, making the mile—equivalent to 1,760 yards—precisely 1,760 × 0.9144 meters. In the imperial system, the international mile equals 5,280 feet (with the international foot defined as exactly 0.3048 ) or 8 furlongs, providing a standardized subdivision for practical applications. This contrasts with historical miles, which varied due to inconsistencies in prototype standards; the 1959 definition ties the unit directly to the meter, ensuring global reproducibility and eliminating discrepancies of up to 2 parts per million from earlier English statute mile implementations. The international mile holds legal status in several countries that retain alongside or instead of the . In the , it is the prescribed unit for road traffic signage and speed limits under the Weights and Measures Act 1985, where it is defined as 1,760 yards of 0.9144 meters each. In , although road distances are marked in kilometers, the international mile remains a lawful unit for and other specialized uses per the Weights and Measures Act (R.S.C., 1985, c. W-6), defined as 1,760 yards. Similar retention applies in other nations and the for general non-survey purposes, supporting consistency in road travel and where imperial measures persist.

United States Survey Mile

The United States survey mile is defined as exactly 5,280 US survey feet, equating to 1,609.347218694 meters, which is slightly longer than the international mile of 1,609.344 meters. This unit played a central role in American land measurement, particularly within the (PLSS), also known as the rectangular survey system, which divides public domain lands into a grid of townships measuring 6 miles on each side, further subdivided into 36 one-square-mile sections. The PLSS originated with the , but its implementation expanded significantly during the as the acquired vast western territories, necessitating standardized surveys for settlement, sale, and governance. Surveyors employed chains calibrated to the mile—typically Gunter's chains of 80 chains per mile—to mark boundaries, corners, and subdivisions, ensuring uniform legal descriptions across millions of acres. The survey mile's length derives from the US survey foot, defined as exactly 1,200/3,937 meters (approximately 0.3048006096 meters), a standard codified by Congress in 1866 to align imperial units with the metric system while preserving historical yard and foot measures. This definition, later formalized in the 1893 Mendenhall Order, differed from the international foot (exactly 0.3048 meters) adopted in 1959 for most scientific and commercial purposes, primarily because the survey foot retained the fractional approximation of the meter from the 19th-century international prototype. The distinction, though minor at about two parts per million, accumulated over large distances in geodetic work, prompting its use exclusively in federal land surveys to maintain consistency with early PLSS records. In 2020, the National Institute of Standards and Technology (NIST) and the National Geodetic Survey (NGS) announced the deprecation of the US survey foot, effective December 31, 2022, to eliminate dual standards and support the modernization of the National Spatial Reference System (NSRS). As a result, the survey mile has been phased out in favor of the international mile for new measurements and applications starting January 1, 2023, promoting uniformity in geospatial data and reducing errors in mapping and engineering. It persists, however, in legacy contexts such as interpreting historical PLSS plats, resurveys, and archived coordinates to avoid discrepancies in land titles and boundaries.

Specialized Miles

Nautical Mile

The is a primarily used in maritime and , defined internationally as exactly 1,852 meters. This fixed value, established in 1929 by the , approximates the length of one minute of arc along a meridian of the at the , providing a standardized measure that accounts for the planet's curvature. The historical evolution of the nautical mile traces back to the 17th century, when Dutch and English navigators developed practical sea miles for measuring distances at sea using the log-and-line method. In 1615, Dutch mathematician Willebrord Snellius calculated the Earth's circumference at approximately 24,630 Roman miles, influencing early nautical measurements on Dutch East India Company ships where the log became standard by 1655. English contributions included the 1574 invention of the log-and-line by an unknown navigator and Richard Norwood's 1637 meridian measurement in England, which proposed a sea mile of about 6,120 feet, later refined through 18th- and 19th-century surveys like the French Academy's 1735–1743 expeditions. By the late 19th century, variations persisted until international efforts culminated in the 1929 standardization, with the United States adopting it in 1954, replacing its prior value of 1,853.248 meters based on the Clarke Spheroid. In navigation, the nautical mile facilitates precise charting and positioning, as it aligns directly with degrees and minutes of latitude on nautical charts, enabling accurate course plotting and distance estimation for safe passage. Speed is measured in knots, where one knot equals one nautical mile per hour, a convention originating from the knotted lines used in speed logs and retained for its simplicity in maritime operations. The International Maritime Organization (IMO) mandates the use of nautical miles in global standards, such as collision avoidance regulations (COLREGs) and visibility requirements, where distances like buoy detection ranges are specified in nautical miles to ensure uniformity across international waters. Related nautical units include the cable, defined as one-tenth of a or approximately 185.2 meters, historically derived from the length of a ship's cable (often 100 fathoms) and used for shorter-range measurements in and anchoring.

Geographical Mile

The is defined as the length corresponding to one minute of arc (1/60 of a degree) along a meridian, representing the distance for a one-minute change in on Earth's surface. This unit varies with latitude due to the planet's oblate spheroid shape, being shorter at the (approximately 1,843 meters) and longer at the poles (approximately 1,862 meters), with an average value of about 1,853.2 meters near 45° latitude. The concept emerged from early geodetic measurements, with French astronomer proposing foundational work by accurately determining the length of one degree of the meridian near in 1669–1670 through , yielding an that enabled the definition of such arc-based units. This measurement, covering about 13 triangles over 80 miles north of , provided the first precise estimate of Earth's radius and was instrumental in 18th- and 19th-century surveying and astronomical applications, where the served as a theoretical standard for calculating planetary dimensions and map projections. In distinction from the nautical mile, the geographical mile remains a variable theoretical construct tied to local arc length, whereas the nautical mile is a fixed of exactly 1,852 meters adopted for practical . Today, the geographical mile has become obsolete in routine use, supplanted by the meter in the , though it persists in specialized geodetic and astronomical computations involving Earth's curvature, such as meridian distance approximations on reference ellipsoids. The nautical mile traces its origins to this geodetic concept but was standardized for uniformity.

Metric Approximations

In practical conversions between the imperial mile and the , the international mile is commonly approximated as 1.61 kilometers for educational purposes and quick calculations, as provided by the U.S. National Institute of Standards and Technology (NIST) in its conversion guidelines. This approximation facilitates everyday use, such as estimating distances in mixed-unit environments, where multiplying miles by 1.61 yields a close kilometer equivalent without requiring precise values like the exact 1.609344 km definition. In athletics, the term "metric mile" specifically refers to the 1500-meter race, a standard middle-distance event that serves as the metric counterpart to the traditional , distinct from exact conversions. Originally contested as 1609 meters in the United States and , the distance was standardized to 1500 meters to align with metric principles while maintaining competitive symmetry on 400-meter tracks, and it has been an Olympic event since 1896 for men and 1972 for women. This usage emphasizes tactical racing over precise equivalence to the imperial mile. Historical efforts to bridge imperial and metric systems included proposals during the mid-20th century metrication discussions, where the mile was redefined metrically as exactly 1609.344 meters in 1959 by international agreement to simplify conversions with kilometers. In countries like the United Kingdom undergoing partial metric transition, dual signage reflects these approximations; for instance, since March 2015, new road signs for vehicle height and width restrictions display both imperial (feet/inches) and metric (meters) units to aid drivers familiar with either system, though distance markers remain in miles.

Regional and Miscellaneous Variants

Scandinavian Mile

The historical Swedish mile, known as the mil, was standardized in 1699 as 18,000 aln (ells), equivalent to approximately 10.688 kilometers. This unit, with the aln measuring about 0.5938 meters, served as a key distance measure for land travel and surveying until the adoption of the on January 1, 1889. Prior to 1699, the mil varied regionally but was generally shorter, often tied to local customs rather than a uniform standard. In , the historical mil was similarly defined as 18,000 alen (forearms or ells), measuring roughly 11.295 kilometers based on the alen of 0.6275 meters, and was used for land until the metric system's introduction in 1875. Danish variants of the mile, also called mil, were shorter at about 7.532 kilometers, comprising 24,000 Danish feet (each approximately 0.3138 meters). Following metrication, the mil in Sweden was redefined in 1889 as exactly 10 kilometers, a metric-derived unit primarily used for road distances and signage. Norway adopted the same 10-kilometer mil in 1875, retaining it for similar practical applications in transportation and navigation. This modern form, often marked on milestones and road signs, simplifies longer-distance communication while aligning with the metric framework. Despite full , the term mil persists in everyday Swedish and for distances exceeding a few kilometers, such as in casual travel discussions or readings, where "20 mil" colloquially means 200 kilometers. This cultural retention reflects the unit's deep-rooted familiarity in Nordic contexts, even as official measurements default to kilometers.

Other Non-Standard Miles

The Japanese ri (里), a traditional unit originating in the feudal era, served as a mile-like measure for land division and travel, equivalent to approximately 3.927 kilometers. This length was standardized during the and reflected the integration of Chinese measurement influences into Japanese systems, facilitating administrative and commercial activities across the . In , lesser-known mile variants emerged for local trade and regional administration. The Saxon mil, prevalent in the , measured about 1.257 kilometers, making it suitable for short-distance commerce and property surveys in the . Similarly, the Breslau mile, adopted officially in from 1630, extended to roughly 6.7 kilometers and was used for broader territorial mapping and postal routes in the area around Wrocław (formerly Breslau). These units varied by locality to accommodate practical needs in trade networks. The Ottoman mile (eski mil), employed in the empire's administrative and contexts, was defined as 5,000 Ottoman feet, equaling approximately 1.894 kilometers. This unit supported logistics in trade routes spanning , , and during the empire's peak. In the , the Croatian mile (hrvatska milja), devised by Jesuit cartographer Stjepan Glavač in 1673, was a geographical variant set at one-tenth of an equatorial degree, measuring about 11.12 kilometers based on an of 6,371 kilometers; it facilitated early modern mapping in the region. Obsolete Russian units like the verst, measuring 1.0668 kilometers, were occasionally equated to a mile in international contexts despite being roughly two-thirds of the English mile, aiding 19th-century rail and road planning in the empire.

Comparisons and Equivalents

Length Comparisons

The mile has evolved across historical and modern contexts, with lengths varying significantly based on regional definitions and purposes. Historical variants, such as the Roman mile, were shorter and tied to ancient pacing systems, while modern miles are precisely defined relative to the meter for international consistency. These differences highlight the unit's adaptation from empirical measures to standardized metrics, often approximating or contrasting with the meter as a baseline. To illustrate these variations, the following table compares representative mile types, grouped by era, with their exact or approximate lengths in meters. All values are derived from official or authoritative definitions.
Era/GroupMile TypeLength (meters)Notes/Source
HistoricalRoman mile1,480Equivalent to 5,000 Roman feet; used in ancient Roman engineering and travel.
ModernMetric mile1,500Colloquial term for the 1,500-meter distance in track and field events, approximating a statute mile in metric terms.
ModernInternational mile1,609.344Defined as exactly 5,280 international feet; adopted in 1959 for global use.
ModernU.S. survey mile1,609.347Based on 5,280 U.S. survey feet; used in American geodetic surveying.
ModernNautical mile1,852Defined as exactly 1,852 meters since 1929; based on one minute of latitude arc.
ModernGeographical mile1,852Synonymous with the modern nautical mile for navigational purposes. (nautical equivalence)
Regional/ModernScandinavian mil10,000Standardized as exactly 10 kilometers in Sweden and Norway since 1889.
Key differences among these variants provide context for their practical applications. For instance, the is approximately 15% longer than the international mile (1,852 m versus 1,609.344 m), reflecting its basis in Earth's for maritime rather than land measurement. The Scandinavian mil stands out as vastly longer at 10 km, serving as a coarse regional equivalent to about 6.2 international miles, while the metric mile at 1.5 km offers a shorter, athletics-focused approximation. Historically, the Roman mile was roughly 8% shorter than the modern international mile, underscoring the from pace-based estimation to precise . The U.S. survey mile, differing by mere millimeters from the international mile, illustrates subtle national variations in legacy systems.

Conversion Formulas

The international mile, also known as the statute mile, is defined as exactly 1,609.344 , or equivalently 1.609344 kilometers. To convert a in kilometers to international miles, divide by the conversion factor: dmiles=dkm1.609344d_{\text{miles}} = \frac{d_{\text{km}}}{1.609344} Conversely, to convert international miles to kilometers, multiply by 1.609344: dkm=dmiles×1.609344d_{\text{km}} = d_{\text{miles}} \times 1.609344 The survey mile differs slightly and is defined as exactly 5,280 US survey feet, where one US survey foot equals 12003937\frac{1200}{3937} exactly. This yields a length of 5,280×1,2003,937\frac{5{,}280 \times 1{,}200}{3{,}937} , or approximately 1,609.347218694 . The bidirectional conversion to is thus: dm (survey)=dsurvey miles×6,336,0003,937d_{\text{m (survey)}} = d_{\text{survey miles}} \times \frac{6{,}336{,}000}{3{,}937} and inversely, dsurvey miles=dm (survey)×3,9376,336,000d_{\text{survey miles}} = d_{\text{m (survey)}} \times \frac{3{,}937}{6{,}336{,}000} The nautical mile is defined as exactly 1,852 meters, or 1.852 kilometers. The conversion from kilometers to nautical miles follows: dnm=dkm1.852d_{\text{nm}} = \frac{d_{\text{km}}}{1.852} and from nautical miles to kilometers: dkm=dnm×1.852d_{\text{km}} = d_{\text{nm}} \times 1.852 To convert between the (statute) mile and the nautical mile, use the exact ratio derived from their meter equivalents: one international mile equals 1,609.3441,852\frac{1{,}609.344}{1{,}852} nautical miles, approximately 0.868976242. Thus, dnm=dstatute miles×1,609.3441,852d_{\text{nm}} = d_{\text{statute miles}} \times \frac{1{,}609.344}{1{,}852} In the reverse direction, one nautical mile equals 1,8521,609.344\frac{1{,}852}{1{,}609.344} international miles, approximately 1.150779448, so dstatute miles=dnm×1,8521,609.344d_{\text{statute miles}} = d_{\text{nm}} \times \frac{1{,}852}{1{,}609.344}

Cultural and Idiomatic Usage

Idioms and Expressions

The "go the extra mile" refers to making an additional effort beyond what is required or expected, often to achieve better results or show greater dedication. This expression derives directly from a biblical passage in the Gospel of Matthew, where instructs followers in the : "If anyone forces you to go one mile, go with them two miles" (Matthew 5:41, NIV), alluding to allowing soldiers to compel civilians to carry loads for one mile. The phrase entered usage in the early as a for voluntary and perseverance. Another common expression, "missed by a mile," describes failing to achieve a or hit a target by a significant margin, emphasizing a clear and substantial error rather than a close call. It builds on the literal of in , using to convey degree of inaccuracy, as in or estimation contexts. This usage appears in English literature from the 19th century onward, often in narratives highlighting misjudgment. Related is the proverb "a miss is as good as a mile," which asserts that even a narrow equates to complete defeat, with origins traced to 18th-century English writings and first printed in America in 1788. In , "a country mile" denotes an exceptionally long distance, particularly in rural settings where paths may wind and appear deceptively extended. The term likely emerged in the , possibly alluding to pre-standardized measurements or the meandering nature of country roads that prolong travel. It is frequently used colloquially to exaggerate separation or superiority, as in "winning by a country mile." Biblical references to the mile, such as in Matthew 5:41, provide a foundational literary example of the unit's symbolic role in themes of endurance and excess, influencing proverbial extensions in English proverbs.

Mile in Sports and Measurement Contexts

In athletics, the is a standard event defined as exactly 1,609.344 meters, equivalent to four laps on a standard 400-meter track plus an additional 9.344 meters. This distance has been recognized by for purposes since the early 20th century, with the men's event serving as a prestigious middle-distance race that tests both speed and endurance. A landmark achievement occurred on May 6, 1954, when British runner became the first person to complete the mile in under four minutes, clocking a time of 3:59.4 at Iffley Road Track in , . This sub-four-minute barrier, long considered an elusive physiological limit, spurred subsequent advancements in training and performance, with the current men's standing at 3:43.13 set by in 1999. In international competitions like the Olympics, where metric distances predominate, the 1,500-meter run—often called the "metric mile"—serves as a close equivalent, covering three and three-quarters laps on a 400-meter track and measuring approximately 109 meters shorter than the full mile. This variation accommodates the global shift to the while preserving the tactical and physiological demands of middle-distance racing, as evidenced by Olympic finals where athletes like have excelled in both formats. Beyond athletics, the mile features prominently in land-based transportation and . In the United States, interstate highways use mile markers—green signs posted every mile—to indicate distance from the state's southern or western border, aiding , services, and crews. odometers, standard in American automobiles, accumulate mileage in miles to track total distance traveled, providing essential data for vehicle valuation, maintenance scheduling, and . Cyclists in the U.S. similarly rely on mile-based odometers or bike computers for route tracking, often aligning with road mile markers during long-distance domestic tours and races. In everyday applications, the mile quantifies practical metrics related to efficiency and . Fuel economy for vehicles is commonly expressed in miles per (), a standard established by the U.S. Environmental Protection Agency and to evaluate . Fitness trackers, such as those from or , convert pedometer-recorded steps into estimated miles walked or run—typically assuming 2,000 to 2,500 steps per mile depending on stride length—to motivate users toward daily goals like 10,000 steps, equivalent to roughly 4 to 5 miles. These conversions promote accessible monitoring by translating biomechanical into familiar distance units.

References

  1. https://physics.nist.gov/cuu/pdf/sp811.pdf
  2. https://www.nist.gov/pml/us-surveyfoot/revised-unit-conversion-factors
  3. https://www.etymonline.com/word/mile
  4. https://www.nist.gov/document/appb-12-hb44-finalpdf
  5. https://www.nist.gov/document/appc-16-hb44-finalpdf
  6. https://www.nist.gov/pml/us-surveyfoot
  7. https://ihr.iho.int/articles/the-nautical-mile/
  8. https://bringbackthemile.com/history
  9. https://www.merriam-webster.com/dictionary/mile
  10. https://www.oed.com/dictionary/mile_n1?tl=true
  11. https://www.bringbackthemile.com/history
  12. https://www.etymonline.com/word/milliary
  13. https://nvlpubs.nist.gov/nistpubs/Legacy/circ/nbscircular47.pdf
  14. https://www.faa.gov/air_traffic/publications/atpubs/cnt_html/appendix_d.html
  15. https://m.measurementconversions.org/lengths/abbreviations.htm
  16. https://learn.microsoft.com/en-us/style-guide/a-z-word-list-term-collections/term-collections/units-of-measure-terms
  17. http://xahlee.info/comp/unicode_units.html
  18. https://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Milliare.html
  19. https://imperiumromanum.pl/en/roman-economy/roman-measures/
  20. http://www.ce.memphis.edu/1101/notes/surveying/surveying_2_distance.pdf
  21. https://www.sizes.com/units/schoinos.htm
  22. https://www.jstor.org/stable/295030
  23. http://kiwihellenist.blogspot.com/2023/06/eratosthenes-2b.html
  24. https://www.jphogendijk.nl/IGAIW/Volume3EN.pdf
  25. https://hal.science/hal-02264631/document
  26. https://press.uchicago.edu/books/hoc/HOC_V2_B1/HOC_VOLUME2_Book1_chapter8.pdf
  27. https://kig.kartografija.hr/index.php/kig/article/view/704
  28. https://www.jstor.org/stable/1523279
  29. https://magnacartaresearch.org/read/magna_carta_1215/Clause_35
  30. https://www.sizes.com/units/mile_welsh.htm
  31. https://www.sizes.com/units/mile_danish.htm
  32. https://www.sizes.com/units/mile_italian.htm
  33. https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors
  34. https://www.govinfo.gov/content/pkg/FR-1959-07-01/pdf/FR-1959-07-01.pdf
  35. https://laws-lois.justice.gc.ca/eng/acts/w-6/page-7.html
  36. https://www.federalregister.gov/documents/2020/10/05/2020-21902/deprecation-of-the-united-states-us-survey-foot
  37. https://www.blm.gov/sites/default/files/histrect.pdf
  38. https://oceanservice.noaa.gov/facts/nautical-mile-knot.html
  39. https://www.hetscheepvaartmuseum.com/collection/articles/707/knots-and-miles-measuring
  40. https://usma.org/laws-and-bills/adoption-of-international-nautical-mile
  41. https://www.marineinsight.com/guidelines/nautical-mile-knot-units-used-sea/
  42. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/AssemblyDocuments/A.222%287%29.pdf
  43. https://www.usni.org/magazines/proceedings/1949/november/nautical-mile
  44. https://www.usgs.gov/faqs/how-much-distance-does-a-degree-minute-and-second-cover-your-maps
  45. https://www.thoughtco.com/degree-of-latitude-and-longitude-distance-4070616
  46. https://www.lindahall.org/about/news/scientist-of-the-day/jean-picard/
  47. https://www.jstor.org/stable/2562946
  48. https://www.transnav.eu/files/So_What_is_Actually_the_Distance_from_the_Equator_to_the_Pole__Overview_of_the_Meridian_Distance_Approximations%2C435.pdf
  49. https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric
  50. https://worldathletics.org/disciplines/middlelong/1500-metres
  51. https://www.bbc.com/news/uk-29965935
  52. https://www.hhogman.se/old-units-of-measurement-sweden.htm
  53. https://www.familysearch.org/en/wiki/Norway_Weights_and_Measurement
  54. https://www.sizes.com/units/mile.htm
  55. https://www.hhogman.se/road-history-2-swe.htm
  56. https://blogs.transparent.com/swedish/the-swedish-mile/
  57. https://www.nippon.com/en/japan-data/h01561/
  58. https://cp.copernicus.org/preprints/cp-2020-92/cp-2020-92-manuscript-version2.pdf
  59. https://doukhobor.org/terms-weights/
  60. https://www.britannica.com/science/league-measurement
  61. https://www.collinsdictionary.com/us/dictionary/english/metric-mile
  62. https://www.nist.gov/document/nist-hb-44-2024-appendix-c-general-tables-units-measurement
  63. https://www.biblegateway.com/passage/?search=Matthew+5%3A41&version=NIV
  64. https://www.dictionary.com/browse/go-the-extra-mile
  65. https://www.phrases.org.uk/meanings/a-miss-is-as-good-as-a-mile.html
  66. https://grammarist.com/idiom/country-mile/
  67. https://www.phrases.org.uk/meanings/a-country-mile.html
  68. https://worldathletics.org/records/all-time-toplists/middlelong/one-mile/all/men/senior
  69. https://www.guinnessworldrecords.com/records/hall-of-fame/first-sub-four-minute-mile
  70. https://www.ncaa.com/news/trackfield-indoor-men/article/2024-12-05/whats-difference-between-1500-meters-and-mile-events-and-not-just-109
  71. https://www.interstaterestareas.com/helpful-information/
  72. https://www.edmunds.com/car-technology/what-is-an-odometer.html
  73. https://www.nhtsa.gov/press-releases/new-fuel-economy-standards-model-years-2027-2031
  74. https://www.verywellfit.com/how-many-walking-steps-are-in-a-mile-3435916
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