Definition: A square foot (ft²) is a unit of area equal to the area of a square that is 1 foot on each side. It is commonly used in the United States and other countries that use the imperial system.

History/origin: The square foot is derived from the foot, which has ancient origins and was traditionally based on the length of a human foot. Its exact definition has varied throughout history.

Current use: Square feet are widely used for measuring the area of rooms, buildings, land, and other surfaces. It's a standard unit in real estate, construction, and many other fields in the US.