Length is generally described as the longest dimension of an object. Length is a measure of one dimension, whereas area is a measure of two dimensions and volume is a measure of three dimensions.
For the imperial system the commonly used units of length are the inch, the foot, the yard, and the mile.
In the metric system the basic unit of length is the metre and is defined in terms of the speed of light.
A mile is a unit of length equivalent to 5,280 feet or 1,760 yards (about 1,609 metres).
The kilometre (International spelling; SI symbol: km) or kilometer (American spelling) is a unit of length in the metric system, equal to one thousand metres.
1 mile = 1.609344 km