Measurement System by Country

Measurement Systems

There are three primary measurement systems used around the world:

• Metric (SI) — Used by the vast majority of countries. Based on meters, kilograms, and Celsius. Adopted as the international standard.
• US Customary — Used primarily in the United States. Uses inches, pounds, and Fahrenheit. Derived from English units but differs from Imperial in volume measures.
• Imperial — Historically used in the British Empire. While the UK has largely adopted metric, imperial units remain in everyday use for road distances (miles), body weight (stones/pounds), and beer/cider (pints).

Mixed Systems

Many countries officially use metric but retain some traditional units in daily life:

• United Kingdom — Officially metric, but uses miles for road signs, stones for body weight, and pints for beer.
• Canada — Officially metric, but commonly uses Fahrenheit, pounds, and feet/inches in everyday conversation.
• Myanmar & Liberia — Among the few countries besides the US that have not officially adopted the metric system, though both are transitioning.

This tool shows each country's official system along with the commonly used units for everyday measurements.