the system of measurement that uses the metre, the kilogram and the litre as basic units 公制;米制 CultureIn the metric system, measurements are based on a single basic unit, for example the metre for length and the kilogram for mass. Other units of measurement are 10, 100, 1 000, etc. times smaller or larger than these. Some metric units of measure are spelt differently in British and American English: words ending in -metre and -litre in British English end in -meter and -liter in American English. The metric system is widely used in Britain, although older people may still measure things using the imperial system, and distances on road signs are still given in miles.