Unit of length whose value has varied in different countries and periods. The Roman mile (mille passus) was equal to 1,482 m. The nautical (or geographic) mile is the length of a terrestrial meridian arc equal to 1' of latitude, and its international value is set at 1,852 m. The land mile or statute mile, used mainly in the United Kingdom and the United States, is equal to 1,609.35 m (5,280 feet).