Metrication or metrification is the act or process of converting to the metric system of measurement. All over the world, countries have transitioned from local and traditional units of measurement to the metric system. This process began in France during the 1790s, and is still continuing more than 200 years later, with the modern International System of Units, as the metric system has not been fully adopted in all countries and areas.
Today, most countries have the metric system as their official system of measurement. Some have adopted it as their official system but have not yet completed the process of metrication. Some others have not made any commitment to adopting it. There is not a general consensus in the sources as to the number of countries that fall into each of these categories.
According to the U.S. Central Intelligence Agency's The World Factbook (2023), the only countries that have not fully adopted the metric system are Myanmar, Liberia, and the