The two major systems of measurement in use in the world are the U.S. Customary System of measurement and the International System of Units, commonly known as the metric system. The majority of the world uses the metric measuring system.
Use of the metric system in business and industry is growing in the United States. The trend has been led by the U.S. Federal Government, which has been required by legislation to use the metric system in many areas of activity since 1992.
The U.S. Customary System of measurement derives from the British Imperial System of measurement. The British Imperial System has been superseded by the metric system and is no longer used in an official capacity. According to the CIA World Factbook, the United States, Burma and Liberia are the only nations that have not adopted the metric system as the official system of measurement.