# Kilometre

1 kilometre =
International units
1000 m km
1×106 mm 10×1012 Å
6.685×10−9 AU 105.7×10−15 LY
US customary / Imperial units
39.37×103 in 3280.84 ft
1093.613 yd 0.621 mi

A kilometre (US spelling: kilometer; symbol: km) is a unit of length that is equal to 1,000 metres, the current International System of Units (SI) base unit of length. The kilometre is part of the metric system. A corresponding unit of area is the square kilometre and a corresponding unit of volume is the cubic kilometre.

Slang terms for kilometre include "klick" (sometimes spelled "click" or "klik") and "kay" (or "k"). These non-standard terms can also refer to kilometres per hour, which itself is abbreviated as km/h, kmh-1 or informally, kph.

Kilometrage is used in a similar way to mileage.

In English, the word "kilometre" is often pronounced with the stress on the second syllable (ki-lom-etre or ki-lom-eter), unlike other SI units (such as kilogram) where the stress is placed on the first syllable (kilo-metre or kilo-meter). It is also a deviation from the pronunciation pattern of all of the other metric prefixes used with the metre unit. Additionally, this different pronunciation follows the alternate pattern of pronunciation that typically applies to measuring devices such as barometer and thermometer.

hectometre << kilometre << megametre

## Equivalence to other units of length

1 kilometre is equal to:

• 1,000 metres (1 metre is equal to 0.001 kilometres)
• about 0.621 statute miles (1 statute mile is equal to 1.609344 kilometres)
• about 1,094 international yards (1 international yard is equal to 0.0009144 kilometres)
• about 3,281 feet (1 foot is equal to 0.0003048 kilometres)

## International usage

Virtually all countries of the world use the kilometre as a standard measure of distance, particularly on road network signage to indicate distances to cities, towns, villages and suburbs etc. The USA is gradually metricating its road signage, but given the magnitude of the country and the sheer amount of signage to be altered or replaced, it is likely to take another generation until the project is complete, even though the USA is officially a nonmetricated nation.[citation needed] Proposals to introduce metric signs on the federally owned interstate highways met with overwhelming public opposition, and the National Highway System Designation Act of 1995 prohibited the use of federal-aid highway funds to convert existing signs or purchase new signs with metric units. [1] (See also Metrication in the United States.)

The main exception to the use of the kilometre as a standard notation of distance is the UK, which has no immediate intention of replacing the mile in the near future, a decision borne mainly out of the British public's attachment to traditional imperial units of distance, ie, miles, yards and inches. Unlike the USA, the UK officially adopts the metric measurement system, so the continuing use of the mile is somewhat of an oddity.

It is possible that at some point in the future, the European Union's Commission may apply pressure upon the UK to conform with the rest of its member states in adopting the kilometre on all of its road signage. Organisations such as the UK Metric Association (UKMA), which is supported by a number of politicians from all parties, have attempted to raise awareness of what it calls 'a very British mess'. Aside from the UK, only the United States, Liberia, and Burma (Myanmar) continue to use the mile.

Sprint cycling is commonly held over a 1 kilometre distance. The kilometre run is a middle distance track event.

## Unicode symbols

For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:

They are useful only with East Asian fixed-width CJK fonts, because they are equal in size to one Chinese character.