While most of the rest of the world uses the metric system (formally known as the International System of Units, or SI), the United States uses the U.S. Customary System, which—fun fact—is ...

In the meantime, a new system of weights and measures, developed by French scientists following the Revolution of 1789, gained increasing international use. This metric system had as its fundamental ...

All countries use the metric system to varying degrees. Most of the world has adopted the metric system as their official system of measurement with one major exception: the United States.