When Was the Metric System Adopted?

The metric system was first legally adopted in France on 7 April 1795 (18 Germinal, Year III in the French Republican Calendar), following work by the French Academy of Sciences to create a rational, decimal-based measurement system. The metre was originally defined as one ten-millionth of the distance from the North Pole to the Equator. The Treaty of the Metre (1875) established an international bureau to maintain standards. Today virtually every country uses the metric system; the US, Liberia, and Myanmar are notable exceptions for everyday use.