Miles to US Survey Miles (mi to mi (US))

1 mile equals 0.999998 US survey miles exactly.

1 mile = 0.999998 US survey miles

How to convert miles to US survey miles

To convert miles to US survey miles, multiply the number of miles by 0.999998. This factor is exact. To go the other way, multiply US survey miles by 1.000002 (rounded).

US survey miles = miles × 0.999998

Example: 10 miles = 9.99998 US survey miles.

About these units

Mile (mi)

US & ImperialCurrent unit

5,280 feet or 1,760 yards, exactly 1,609.344 meters. This is the statute (international) mile used on US and UK roads.

A thousand paces gave the mile its name. It descends from the Latin mille passus, the Roman mile, by way of Old English mil and Middle English myle. For centuries after Rome, miles of many lengths coexisted; a sixteenth-century Mercator map, for example, shows small, medium and large Flemish miles on a single scale bar. The English statute mile was fixed by an Act of Parliament under Elizabeth I in 1593, which declared that a mile contains eight furlongs, or 5,280 feet.

The 1959 international yard and pound agreement made that mile exactly 1,609.344 meters. A slightly longer US survey mile, about 1,609.347 meters, lingered in American land surveys and was slated for retirement from 1 January 2023. Today the mile is the road unit of the United Kingdom, the United States, Liberia and Myanmar, along with several territories such as the Bahamas, Belize, Guam and the US Virgin Islands. In Canada it survives chiefly in rail transport and horse racing.

1 mile = 1,609.344 meters (exactly).

Sources: Wikipedia: Mile; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors

US Survey Mile (mi (US))

US land surveyHistorical unit (no longer in standard use)

5,280 US survey feet (about 1,609.347 m). Slightly longer than the international mile, used in US land surveys until 2022.

Because it is built from 5,280 survey feet, this mile inherits the survey foot's tiny excess and comes to about 1,609.347 m, against exactly 1,609.344 m for the international mile. The gap is under 1/8 inch, or 3.2 mm, per mile, and one international mile equals 0.999998 survey miles. In US law the formal statute mile was the survey mile, though everyday usage treats the two as the same.

Over a single trip the difference vanishes, but State Plane Coordinate Systems can stretch across hundreds of miles, where a few millimetres per mile accumulate into something a surveyor must account for. For that reason surveyors kept the survey mile long after the international foot took over elsewhere. In October 2019 the National Geodetic Survey and NIST announced that the survey foot and mile would be retired from 1 January 2023, and NIST says the unit now survives only for historic and legacy data. Maps and deeds written before then still use it.

1 US survey mile = 1,609.347219 meters (approximately).

Sources: Wikipedia: Mile; NIST: U.S. survey foot

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