Mile

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mile
international |US survey |nautical
km km 1.852 km
1,609.344 m 1,609.347 m 1,852 m


A mile is a unit
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...

 of length
Length
In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...

, most commonly 5,280 feet (1,760 yards, or about 1,609 metres). The mile of 5,280 feet is sometimes called the statute mile or land mile to distinguish it from the nautical mile
Nautical mile
The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...

(1,852 metres, about 6,076.1 feet). There have also been many historical miles and similar units in other systems that may be translated as miles in English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

; they have varied in length between one and 15 kilometres.

The exact length of the land mile varied slightly among English-speaking countries until an international agreement in 1959 established the yard as exactly 0.9144 metres, giving a mile of exactly 1,609.344 metres. The United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 adopted this international mile for most purposes, but retained the pre-1959 mile for some land-survey data, terming it the US survey mile. In the US, statute mile formally refers to the survey mile, about 3.2 mm (⅛ inch) longer than the international mile (the international mile is exactly 0.0002% less than the US survey mile).

Use of the mile as a unit of measurement is now largely confined to the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and the United States.

Origin


The word mile originally derives from the Old English word mīl which in turn was ultimately derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 word millia meaning "thousand". The English mile is derived from the Latin mille passuum (one thousand paces) but in other countries the word "mile" (meile in German, mijl in Dutch) was derived from the Latin miliarium spatium (one thousand "intervals").

Roman mile


The Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 were first to use the unit of long distance (literally "a thousand paces" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

, where each pace was two steps). It denoted a distance of 1,000 paces or 5,000 Roman feet, and is estimated to be about 1,479 metres (1,617 yards). This unit, now known as the Roman mile, spread throughout the Roman Empire, often with modifications to fit local systems of measurement
Systems of measurement
A system of measurement is a set of units which can be used to specify anything which can be measured and were historically important, regulated and defined because of trade and internal commerce...

s.

Historical miles in the Arabic world and Europe

  • The Arab mile
    Arab mile
    The Arab mile is a historical unit of length. Its precise length is uncertain, lying between 1.9 and 2.0 km. It is used by medieval Arab geographers....

     (or Arabic mile) was a unit of length used by medieval Muslim geographers. Its precise length is uncertain, but is believed to be around 1925 metres.
  • The Danish (traditional) was 24,000 Danish feet or 7532.5 metres. Sometimes it was interpreted as exactly 7.5 kilometres. It is the same as the north German (below).
  • The was a traditional unit in German-speaking countries. It was 24,000 German feet; the SI equivalent was 7586 metres in Austria or 7532.5 metres in northern Germany. There was a version known as the , which was 4 Admiralty nautical miles, 7,412.7 metres, or 1/15 of a degree of latitude.
  • In Norway and Sweden, a mil is a unit of length equal to 10 kilometres and commonly used in everyday language. However in more formal situations, such as on road signs and when there is risk of confusion with English miles, kilometres are used instead. The traditional Swedish spanned the range from 6000-14,485 metres, depending on province
    Provinces of Sweden
    The provinces of Sweden, landskap, are historical, geographical and cultural regions. Sweden has 25 provinces and they have no administrative function, but remain historical legacies and the means of cultural identification....

    . It was however standardized in 1649 to 36,000 Swedish feet, or 10.687 km. The Norwegian was 11.298 kilometres. When the metric system
    Metric system
    The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...

     was introduced in the Norwegian-Swedish union
    Union between Sweden and Norway
    The Union between Sweden and Norway , officially the United Kingdoms of Sweden and Norway, consisted of present-day Sweden and Norway between 1814 and 1905, when they were united under one monarch in a personal union....

     in 1889, it standardized the to exactly 10 kilometres. Mil is still commonly used when measuring fuel consumption in vehicles; e.g., 0.5 litre per mil.
  • The Portuguese milha was a unit of length used in Portugal
    Portugal
    Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

     and Brazil
    Brazil
    Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

    , before the adoption of the metric system. It was equal to 2087.3 metres.
  • The Russian was a traditional Russian unit of distance, equal to 7 verst, or 7.468 km.
  • The (Croatian mile) is 11,130 metres = 11.13 km = 1/10 of equator's degree, first used by Jesuit Stjepan Glavač on a map from 1673.
  • The (also called ) (mile of Croatian Ban
    Ban (title)
    Ban was a title used in several states in central and south-eastern Europe between the 7th century and the 20th century.-Etymology:The word ban has entered the English language probably as a borrowing from South Slavic ban, meaning "lord, master; ruler". The Slavic word is probably borrowed from...

    , Croatian mile) was 7586 metres = 7.586 kilometres, or 24,000 feet (the same as the Austrian mile).

Historical miles in Britain and Ireland


The statute mile (1593) of Elizabeth I was not the only definition of the mile in Britain and Ireland. Perhaps the earliest tables of English linear measures, Arnold's Customs of London (c. 1500) indicates a mile consisted of 8 furlongs, each of 625 feet, for a total of 5000 feet (1666⅔ yards, 0.947 statute miles, 1524 metres): this is the same definition of the mile in terms of feet as used by the Romans. The "old English" mile of medieval and early modern times appears to have measured about 1.3 statute miles (1.9 km). The 17th century cartographer, Robert Morden
Robert Morden
Robert Morden was a British bookseller, publisher, and maker of maps and globes.He was among the first successful commercial map makers....

, had multiple scales on his maps—for example, his map of Hampshire
Hampshire
Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...

 showed two different miles that had a ratio of and his map of Dorset
Dorset
Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...

 had three scales with a ratio of . In both cases, the smallest mile appears to be the statute mile.

Scots mile



The Royal Mile
Royal Mile
The Royal Mile is a succession of streets which form the main thoroughfare of the Old Town of the city of Edinburgh in Scotland.As the name suggests, the Royal Mile is approximately one Scots mile long, and runs between two foci of history in Scotland, from Edinburgh Castle at the top of the Castle...

 in Edinburgh
Edinburgh
Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...

, i.e., from the Castle
Edinburgh Castle
Edinburgh Castle is a fortress which dominates the skyline of the city of Edinburgh, Scotland, from its position atop the volcanic Castle Rock. Human habitation of the site is dated back as far as the 9th century BC, although the nature of early settlement is unclear...

 down to Holyrood Abbey
Holyrood Abbey
Holyrood Abbey is a ruined abbey of the Canons Regular in Edinburgh, Scotland. The abbey was founded in 1128 by King David I of Scotland. During the 15th century, the abbey guesthouse was developed into a royal residence, and after the Scottish Reformation the Palace of Holyroodhouse was expanded...

, is approximately the same length as the Scots mile. English miles were imposed in 1824 by an Act of Parliament
Act of Parliament
An Act of Parliament is a statute enacted as primary legislation by a national or sub-national parliament. In the Republic of Ireland the term Act of the Oireachtas is used, and in the United States the term Act of Congress is used.In Commonwealth countries, the term is used both in a narrow...

.

Equivalent to:
  • Scottish measures
    Obsolete Scottish units of measurement
    Scotland had a distinct system of measures and weights until at least the late 18th century, based on the ell as a unit of length, the stone as a unit of mass and the boll and the firlot as units of dry measure...

    : 320 falls
    Fall (Scots)
    A fall or fa’ a Scottish measurement of length. Other variants of the name include "faw", "faa" and "fa", the spelling with an apologetic apostrophe is not favoured now...

    ; or 8 Scots furlongs
  • Metric system
    Metric system
    The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...

    : 1807 metres
  • Imperial system: 1,976 yards (about 1.12 miles)


Robert Burns
Robert Burns
Robert Burns was a Scottish poet and a lyricist. He is widely regarded as the national poet of Scotland, and is celebrated worldwide...

 spoke of Scots miles in the first verse of Tam O' Shanter
Tam o' Shanter (Burns poem)
"Tam o' Shanter" is a poem written by the Scottish poet Robert Burns in 1790. Many consider it to be one of the best examples of the narrative poem in modern European literature....


"While we sit bousing at the nappy,
An' getting fou and unco happy,
We think na on the lang Scots miles,
The mosses, waters, slaps and stiles,
That lie between us and our hame,
Where sits our sulky, sullen dame,
Gathering her brows like gathering storm,
Nursing her wrath to keep it warm."


The Scots mile was longer than the English mile, but varied in length from place to place. It was formally abolished by an Act of the Parliament of Scotland
Parliament of Scotland
The Parliament of Scotland, officially the Estates of Parliament, was the legislature of the Kingdom of Scotland. The unicameral parliament of Scotland is first found on record during the early 13th century, with the first meeting for which a primary source survives at...

 in 1685, and again by the Treaty of Union with England in 1707, but continued in use as a customary unit during the 18th century. It was obsolete by the time of its final abolition by the Weights and Measures Act 1824. An estimate of its length can be made from other Scots units
Obsolete Scottish units of measurement
Scotland had a distinct system of measures and weights until at least the late 18th century, based on the ell as a unit of length, the stone as a unit of mass and the boll and the firlot as units of dry measure...

: in Scots, the rod
Rod (unit)
The rod is a unit of length equal to 5.5 yards, 5.0292 metres, 16.5 feet, or of a statute mile. A rod is the same length as a perch or a pole. In old English, the term lug is also used.-History:...

 was usually called the fall or faw, and was equal to six ell
Ell
An ell , is a unit of measurement, approximating the length of a man's arm.Several national forms existed, with different lengths, includingthe Scottish ell ,the Flemish ell ,the French ell...

s of 37 inches. As there are 320 rods in a mile and 1.0016 Imperial inches in a Scots inch, this would make the Scots mile equal to 5,920 Scots feet (1,976.5 imperial yards, 1.12 statute miles). Other estimates are similar.

Irish mile


The Irish mile was longer still. In Elizabethan times, four Irish miles was often equated to five English, though whether the statute mile or the "old English" mile is unclear. By the seventeenth century, it was 2,240 yards (6,720 feet, 1.27 statute miles, 2,048 metres). Again, the difference arose from a different length of the rod in Ireland (usually called the perch locally): 21 feet as opposed to 16½ feet in England.

From 1774, through the 1801 union with Britain, until the 1820s, the grand juries
Grand jury
A grand jury is a type of jury that determines whether a criminal indictment will issue. Currently, only the United States retains grand juries, although some other common law jurisdictions formerly employed them, and most other jurisdictions employ some other type of preliminary hearing...

 of 25 Irish counties commissioned surveyed maps at scales of one or two inches per Irish mile. Scottish engineer William Bald's County Mayo
County Mayo
County Mayo is a county in Ireland. It is located in the West Region and is also part of the province of Connacht. It is named after the village of Mayo, which is now generally known as Mayo Abbey. Mayo County Council is the local authority for the county. The population of the county is 130,552...

 maps of 1809–30 were drawn in English miles and rescaled to Irish miles for printing. The Howth
Howth
Howth is an area in Fingal County near Dublin city in Ireland. Originally just a small fishing village, Howth with its surrounding rural district is now a busy suburb of Dublin, with a mix of dense residential development and wild hillside, all on the peninsula of Howth Head. The only...

Dublin Post Office
General Post Office (Dublin)
The General Post Office ' in Dublin is the headquarters of the Irish postal service, An Post, and Dublin's principal post office...

 extension of the London–Holyhead turnpike engineered by Thomas Telford
Thomas Telford
Thomas Telford FRS, FRSE was a Scottish civil engineer, architect and stonemason, and a noted road, bridge and canal builder.-Early career:...

 had mileposts in English miles. Although legally abolished by the Weights and Measures Act 1824, the Irish mile was used till 1856 by the Irish Post Office. The Ordnance Survey of Ireland, from its establishment in 1824, used English miles.

In 1894, Alfred Austin
Alfred Austin
Alfred Austin was an English poet who was appointed Poet Laureate in 1896 upon the death of Alfred, Lord Tennyson.-Life:...

 complained after visiting Ireland that "the Irish mile is a fine source of confusion when distances are computed. In one county a mile means a statute mile, in another it means an Irish mile". When the Oxford English Dictionary
Oxford English Dictionary
The Oxford English Dictionary , published by the Oxford University Press, is the self-styled premier dictionary of the English language. Two fully bound print editions of the OED have been published under its current name, in 1928 and 1989. The first edition was published in twelve volumes , and...

 definition of "mile" was published in 1906, it described the Irish mile as "still in rustic use". A 1902 guide says regarding milestone
Milestone
A milestone is one of a series of numbered markers placed along a road or boundary at intervals of one mile or occasionally, parts of a mile. They are typically located at the side of the road or in a median. They are alternatively known as mile markers, mileposts or mile posts...

s, "Counties Dublin
County Dublin
County Dublin is a county in Ireland. It is part of the Dublin Region and is also located in the province of Leinster. It is named after the city of Dublin which is the capital of Ireland. County Dublin was one of the first of the parts of Ireland to be shired by King John of England following the...

, Waterford
County Waterford
*Abbeyside, Affane, Aglish, Annestown, An Rinn, Ardmore*Ballinacourty, Ballinameela, Ballinamult, Ballinroad, Ballybeg, Ballybricken, Ballyduff Lower, Ballyduff Upper, Ballydurn, Ballygunner, Ballylaneen, Ballymacarbry, Ballymacart, Ballynaneashagh, Ballysaggart, Ballytruckle, Bilberry, Bunmahon,...

, Cork
County Cork
County Cork is a county in Ireland. It is located in the South-West Region and is also part of the province of Munster. It is named after the city of Cork . Cork County Council is the local authority for the county...

, Antrim
County Antrim
County Antrim is one of six counties that form Northern Ireland, situated in the north-east of the island of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 2,844 km², with a population of approximately 616,000...

, Down
County Down
-Cities:*Belfast *Newry -Large towns:*Dundonald*Newtownards*Bangor-Medium towns:...

, and
Armagh
County Armagh
-History:Ancient Armagh was the territory of the Ulaid before the fourth century AD. It was ruled by the Red Branch, whose capital was Emain Macha near Armagh. The site, and subsequently the city, were named after the goddess Macha...

 use English, but Donegal
County Donegal
County Donegal is a county in Ireland. It is part of the Border Region and is also located in the province of Ulster. It is named after the town of Donegal. Donegal County Council is the local authority for the county...

 Irish Miles; the other counties either have both, or only one or two roads have Irish". Variation in signage persisted till the publication of standardised road traffic regulations by the Irish Free State
Irish Free State
The Irish Free State was the state established as a Dominion on 6 December 1922 under the Anglo-Irish Treaty, signed by the British government and Irish representatives exactly twelve months beforehand...

 in 1926. In 1937, a man prosecuted for driving outside the 15-mile limit of his licence offered the unsuccessful defence that, since the state was independent, the limit ought to use Irish miles, "just as no one would ever think of selling land other than as Irish acre
Acre (Irish)
An Irish acre is a unit of area historically used in Ireland, Yorkshire, and regions bordering the Solway Firth.One Irish acre is equal to about 1.62 acre, 7,840 square yards, or 70,560 square feet....

s". A 1965 proposal by two TD
Teachta Dála
A Teachta Dála , usually abbreviated as TD in English, is a member of Dáil Éireann, the lower house of the Oireachtas . It is the equivalent of terms such as "Member of Parliament" or "deputy" used in other states. The official translation of the term is "Deputy to the Dáil", though a more literal...

s to replace statute miles with Irish miles in a clause of the Road Transport Act was rejected. The term is now obsolete as a specific measure, though an "Irish mile" colloquially is a long but vague distance akin to a "country mile".

Statute mile


The statute mile was so-named because it was defined by an English Act of Parliament
Act of Parliament
An Act of Parliament is a statute enacted as primary legislation by a national or sub-national parliament. In the Republic of Ireland the term Act of the Oireachtas is used, and in the United States the term Act of Congress is used.In Commonwealth countries, the term is used both in a narrow...

 in 1593, during the reign of Queen Elizabeth I
Elizabeth I of England
Elizabeth I was queen regnant of England and Ireland from 17 November 1558 until her death. Sometimes called The Virgin Queen, Gloriana, or Good Queen Bess, Elizabeth was the fifth and last monarch of the Tudor dynasty...

. The statute states: "A Mile ſhall contain eight Furlongs, every Furlong forty Poles, and every Pole ſixteen Foot and a half." (35 Eliz. cap. 6.) It was thus 1760 yards (5280 feet, about 1609 metres). For surveying
Surveying
See Also: Public Land Survey SystemSurveying or land surveying is the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them...

, the statute mile is divided into eight furlong
Furlong
A furlong is a measure of distance in imperial units and U.S. customary units equal to one-eighth of a mile, equivalent to 220 yards, 660 feet, 40 rods, or 10 chains. The exact value of the furlong varies slightly among English-speaking countries....

s; each furlong into ten chains
Chain (unit)
A chain is a unit of length; it measures 66 feet or 22 yards or 100 links . There are 10 chains in a furlong, and 80 chains in one statute mile. An acre is the area of 10 square chains...

; each chain into four rods
Rod (unit)
The rod is a unit of length equal to 5.5 yards, 5.0292 metres, 16.5 feet, or of a statute mile. A rod is the same length as a perch or a pole. In old English, the term lug is also used.-History:...

 (also known as poles or perches
Perch (unit of measure)
A perch is as a unit of measurement used for length, area, and volume in a number of systems of measurement. Its name derives from the Ancient Roman unit, the pertica.-Origin:...

); and each rod into 25 links. This makes the rod equal to 5½ yards or 16½ feet in both Imperial and US usage.

The exact conversion of the mile to SI units depends on which definition of the yard is used. Different English-speaking countries maintained independent physical standards for the yard that were found to differ by small, but measurable, amounts and even to slowly shorten in length. The US redefined the US yard in 1893, but this resulted in US and Imperial measures of distance having very slightly different lengths. The difference was resolved in 1959 with the definition of the international yard in terms of the metre by Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, the UK and the US. The "international mile" of 1760 international yards is exactly 1609.344 metres.

The difference from the previous standards was 2 ppm, or about 3.2 millimetres (⅛ 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 North America was the North American Datum
North American Datum
The North American Datum is the official datum used for the primary geodetic network in North America.In the fields of cartography and land-use there are currently two North American Datums in use: the North American Datum of 1927 and the North American Datum of 1983...

 of 1927 (NAD27). This had been constructed by triangulation
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by measuring angles to it from known points at either end of a fixed baseline, rather than measuring distances to the point directly...

 based on the definition of the foot in the Mendenhall Order
Mendenhall Order
The Mendenhall Order marked a decision to change the fundamental standards of length and mass of the United States from the customary standards based on those of England to metric standards. It was issued on April 5, 1893 by Thomas Corwin Mendenhall, superintendent of the U.S...

 of 1893, with 1 foot =  metres and the definition was retained for data derived from NAD27, but renamed the US survey foot to distinguish it from the international foot.

The US survey mile is 5280 survey feet, or about 1609.347 218 694 metres. In the US, statute mile formally refers to the survey mile, but for most purposes, the difference between the survey mile and the international mile is insignificant—one international mile is exactly 0.999 998 of a US survey mile—so statute mile can be used for either. But in some cases, such as in the US State Plane Coordinate System
State Plane Coordinate System
The State Plane Coordinate System is a set of 124 geographic zones or coordinate systems designed for specific regions of the United States. Each state contains one or more state plane zones, the boundaries of which usually follow county lines...

s (SPCSs), which can stretch over hundreds of miles, the accumulated difference can be significant, so it is important to note that the reference is to the US survey mile.

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.
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.

The old Imperial value of the yard was used in converting measurements to metric values in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 in a 1976 Act of the Indian Parliament. However, The current National Topographic Database of the Survey of India
Survey of India
The Survey of India is India's central engineering agency in charge of mapping and surveying. Set up in 1767 to help consolidate the territories of the British East India Company, it is one of the oldest Engineering Departments of the Government of India...

 is based on the metric WGS-84 datum, which is also used by the Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

.

Metric mile



The term metric mile
Metric mile
Metric mile is a distance which approximates one statute mile at a round figure of metres . The term is most commonly used in track running and swimming....

 is used in sports such as track and field athletics and speed skating
Speed skating
Speed skating, or speedskating is a competitive form of ice skating in which the competitors race each other in traveling a certain distance on skates. Types of speed skating are long track speed skating, short track speed skating, and marathon speed skating...

 to denote a distance of 1500 metres (about 4921 ft). In United States high school competition, the term is sometimes used for a race of 1,600 metres (about 5249 ft).

Nautical mile



The nautical mile was originally defined as one minute of arc
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....

 along a meridian
Meridian arc
In geodesy, a meridian arc measurement is a highly accurate determination of the distance between two points with the same longitude. Two or more such determinations at different locations then specify the shape of the reference ellipsoid which best approximates the shape of the geoid. This...

 of the Earth. 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. 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. Using the WGS84 ellipsoid
World Geodetic System
The World Geodetic System is a standard for use in cartography, geodesy, and navigation. It comprises a standard coordinate frame for the Earth, a standard spheroidal reference surface for raw altitude data, and a gravitational equipotential surface that defines the nominal sea level.The latest...

, the commonly accepted Earth model for many purposes today, one minute of latitude at the WGS84 equator is 6,046 feet and at the poles is 6,107.5 feet. The average is about 6,076 feet (about 1,852 metres or 1.15 statute miles).

In the United States the nautical mile was defined in the 19th century as 6,080.2 feet (1,853.249 m), whereas in the United Kingdom, the Admiralty nautical mile was defined as 6,080 feet (1,853.184 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, but it is now internationally defined to be exactly 1,852 metres.

Related nautical 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
Data mile
In radar-related subjects and in JTIDS, a data mile is a unit of distance equal to 6000 feet , or 0.987 nautical miles. An international mile is exactly 0.88 of a data mile....

 is used in radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

-related subjects and is equal to 6,000 feet (1.8288 kilometres). 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.

Abbreviation and symbol


There have been several abbreviations for mile (with and without trailing period): mi, ml, m, M. In the United States, the National Institute of Standards and Technology
National Institute of Standards and Technology
The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...

 now uses and recommends mi, which avoids confusion with metres, millilitres, etc., but in everyday usage (at least in the United States and in the United Kingdom), units such as miles per hour
Miles per hour
Miles per hour is an imperial unit of speed expressing the number of statute miles covered in one hour. It is currently the standard unit used for speed limits, and to express speeds generally, on roads in the United Kingdom and the United States. It is also often used to express the speed of...

 and miles per gallon are almost always abbreviated as mph or mpg (rather than mi/h or mi/gal).

Grid system


Cities in the continental United States often have street
Street
A street is a paved public thoroughfare in a built environment. It is a public parcel of land adjoining buildings in an urban context, on which people may freely assemble, interact, and move about. A street can be as simple as a level patch of dirt, but is more often paved with a hard, durable...

s laid out by miles. Detroit, Indianapolis
Indianapolis
Indianapolis is the capital of the U.S. state of Indiana, and the county seat of Marion County, Indiana. As of the 2010 United States Census, the city's population is 839,489. It is by far Indiana's largest city and, as of the 2010 U.S...

, Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

, Phoenix
Phoenix, Arizona
Phoenix is the capital, and largest city, of the U.S. state of Arizona, as well as the sixth most populated city in the United States. Phoenix is home to 1,445,632 people according to the official 2010 U.S. Census Bureau data...

, Philadelphia, Las Vegas
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...

, Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...

, and Miami, are several examples. Typically the largest streets are about a mile apart, with others at half-mile and quarter-mile intervals. In the Manhattan
Manhattan
Manhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...

 borough of New York City "streets" are close to 20 per mile, while the major numbered "avenues" are about six per mile. (Centerline to centerline, 42nd St to 22nd St is supposed to be 5250 feet while 42nd to 62nd is supposed to be 5276 ft 8 in.)

Idioms


Even in English-speaking countries that have moved from the Imperial to the metric system (for example, Australia, Canada, and New Zealand), the mile is still used in a variety of idioms. These 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
    Ell
    An ell , is a unit of measurement, approximating the length of a man's arm.Several national forms existed, with different lengths, includingthe Scottish ell ,the Flemish ell ,the French ell...

    "
    (the person in question will become greedy if shown generosity)
  • "Missed by a mile" (missed by a wide margin)
  • "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
    Milestone
    A milestone is one of a series of numbered markers placed along a road or boundary at intervals of one mile or occasionally, parts of a mile. They are typically located at the side of the road or in a median. They are alternatively known as mile markers, mileposts or mile posts...

    "
    (an event indicating significant progress)

See also



  • Anthropic units
    Anthropic units
    Anthropic units are units of measurement which explicitly arose from human physiology or behavior. Some were derived directly from the dimensions of the human body, and as such, are commonly referred to as anthropomorphic...

  • Data mile
    Data mile
    In radar-related subjects and in JTIDS, a data mile is a unit of distance equal to 6000 feet , or 0.987 nautical miles. An international mile is exactly 0.88 of a data mile....

  • Fibonacci sequence for miles converting to kilometers
  • Food miles
    Food miles
    Food miles is a term which refers to the distance food is transported from the time of its production until it reaches the consumer. Food miles are one factor used when assessing the environmental impact of food, including the impact on global warming....

  • Four-minute mile
    Four-minute mile
    In the sport of athletics, the four-minute mile is the act of completing the mile run in less than four minutes. It was first achieved in 1954 by Roger Bannister in 3:59.4. The 'four minute barrier' has since been broken by many male athletes, and is now the standard of all male professional...


  • Geographical mile
    Geographical mile
    The geographical mile is a unit of length determined by 1 minute of arc along the Earth's equator. For the 1924 International Spheroid this equalled 1855.4 metres...

  • Mile run
    Mile run
    The mile run is a middle-distance foot race which is among the more popular events in track running.The history of the mile run event began in England, where it was used as a distance for gambling races...

  • Section lines
  • Square mile
    Square mile
    The square mile is an imperial and US unit of measure for an area equal to the area of a square of one statute mile. It should not be confused with miles square, which refers to the number of miles on each side squared...

  • United States customary units
    United States customary units
    United States customary units are a system of measurements commonly used in the United States. Many U.S. units are virtually identical to their imperial counterparts, but the U.S. customary system developed from English units used in the British Empire before the system of imperial units was...


External links