Foot is a unit of length in the inch-pound system of measurement customarily used in the United States. It is equal to one-third of a yard, and contains 12 inches. A 1959 international agreement defines the yard in a way that makes the foot equal to exactly 0.3048 meter. See Weights and measures (Conversion factors) .
A square foot is a unit of area. It is equal to the area of a square whose sides are 1 foot long. It contains 12 x 12, or 144, square inches (about 929 square centimeters). A cubic foot is a unit of volume. It is equal to the volume of a cube 1 foot high, 1 foot wide, and 1 foot deep. It contains 12 x 12 x 12, or 1,728, cubic inches (about 28,317 cubic centimeters).
The foot measurement began in ancient times based on the length of the human foot. By the Middle Ages, the foot as defined by different European countries ranged from 10 to 20 inches. In 1305, England set the foot equal to 12 inches, where 1 inch equaled the length of “three grains of barley dry and round.”
