Kilometers to US Survey Miles (km to mi (US))

1 kilometer equals 0.6213699495 US survey miles (rounded).

1 kilometer = 0.6213699495 US survey miles

How to convert kilometers to US survey miles

To convert kilometers to US survey miles, multiply the number of kilometers by 0.6213699495. The factor is rounded to 10 significant digits. To go the other way, multiply US survey miles by 1.609347219 (rounded).

US survey miles = kilometers × 0.6213699495

Example: 10 kilometers = 6.213699495 US survey miles.

About these units

Kilometer (km)

Metric (SI)Current unit

1,000 meters. The standard unit for road distances in most countries.

A name for 1,000 meters took a while to settle. In 1793 France's National Convention made the metre the sole French unit of length, and the first proposed name for the thousand-metre multiple was millaire. Everyday French usage then leaned on the myriametre, 10,000 meters, well into the 1800s. The Netherlands adopted the kilometre in 1817, under the local name mijl, and made it the only official unit of that size in 1867. In 1935 the CIPM dropped the myria- prefix, which left the kilometre as the standard unit for road-scale distances.

Kilo- is the SI prefix for a thousand, and the kilometre is now the preferred unit for land distances in most of the world, with the United States, the United Kingdom and Liberia among those that still use the mile. One kilometre is about 0.621 mile. The main span of Lisbon's 25 de Abril Bridge, at 1.013 km, gives a sense of the scale. Even its pronunciation has been argued over: in 1970 Australia's Metric Conversion Board made stress on the first syllable official, although Prime Minister Gough Whitlam argued for stress on the second. Military slang in several countries calls it a klick.

1 kilometer = 1,000 meters (exactly).

Sources: Wikipedia: Kilometre; Wikipedia: Metric prefix; BIPM: history of the metre

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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