Whatever the true story, the foot we know today is equal to 12 inches (30.48 centimeters). The true standardization of the foot came late in the 19th century, after the United States and Britain signed the “Treaty of the Meter.” In this treaty, the foot was officially defined in terms of the new metric standards being adopted overseas. In the United States, the Metric Act of 1866 further defined the foot as equal to exactly 1,200/3,937 meter, or about 30.48006096 centimeters; this unit of measurement is still used for geodetic surveying purposes in the states, and is called the survey foot. By 1959, the United States National Bureau of Standards redefined the foot to equal exactly 30.48 centimeters—or about 0.999998 survey foot. This definition was also adopted in Britain by the Weights and Measures Act of 1963; thus, a foot, or 30.48 centimeters, is also called the international foot.

King Charlemagne was ruler of the Franks and Emperor of the Romans in the ninth century. He encouraged education during his reign, and some credit him with creating the standard for the foot, based on his own foot size.