Kilometre

A kilometre (American spelling: kilometer, symbol km) is a unit of length in the metric system, equal to one thousand metres, the current SI base unit of length. It can be written in scientific notations as 1×103 m (engineering notation) or 1 E+3 m (exponential notation) — both meaning 1,000 × 1 m.

nanometre <<< micrometre <<< millimetre < centimetre < decimetre < metre < decametre < hectometre < kilometre <<< megametre

In English, the word "kilometre" is often pronounced with the stress on the second syllable (ki-LOM-i-ter) - following the stress pattern that applies to measuring devices (barometer and thermometer) rather than to other multiples of the metre (millimetre, decimetre) or other SI units (kilogram). Where the suffix "meter" is used in a word describing a measuring device, the emphasis is commonly placed on the vowel sound immediately preceding the "meter" suffix. Examples include speedometer, tachometer, spectrometer, altimeter etc. for measurement. When the word describes a unit of measurement (e.g. distance, weight) the emphasis is placed on the initial syllable of the "metre" suffix. Examples include millimetre and centimetre, similar to milligram, centigram and kilogram.

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, km h-1, km·h-1 or, informally, kph.