kilomeetreid

Kilometre, or kilometer, is a unit of length in the metric system. It equals 1000 metres and is a derived unit in the International System of Units (SI). In Estonian, the plural form is kilomeetreid. The kilometre is formed by the SI prefix kilo- combined with the metre.

The metre was redefined in 1983 as the distance light travels in vacuum in 1/299,792,458 of a second, making the kilometre equal to 1000 metres. Kilometres are widely used to express longer distances where metres would be too cumbersome, such as road distances, geographic extents, and athletic events. For practical use, 1 kilometre equals 1000 metres, and 1 kilometre is approximately 0.621371 miles. In maps and signage, kilometres are typically used for distances between cities, while in some contexts other units, such as miles or nautical miles, may be used depending on country and application.

For longer measurements, even larger SI units such as the megametre (Mm) are used in scientific contexts, where 1 Mm equals 1,000,000 metres. Kilometres also feature in everyday life and transportation, from road signs indicating travel distance to the length of races and geographic surveys. The term kilomeeter is the Estonian root, with kilomeetreid as the standard plural form in language usage.