The square foot (plural square feet; abbreviated sq. ft, sf, or ft2; also denoted by '2) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States and partially in Canada, the United Kingdom, Bangladesh, India, Nepal, Pakistan, Ghana, Liberia, Malaysia, Myanmar, Singapore and Hong Kong. It is defined as the area of a square with sides of 1 foot. 1 Square foot conversion to other units of area: