how many sf in an acre
âºâº Definition: Acre. An acre is a measure of land area in Imperial units or U.S. customary units. It is equal to 43 560 square feet, 4840 square yards, or 160 square rods. The precise meaning of this depends on the exact definition adopted for a foot: the international acre is 4 046.856 422 4 m (for the UK, see).t is equal to 43 560 square feet, 4840 square yards, or 160 square rods. The precise meaning of this depends on the exact definition adopted for a foot: the international acre is 4 046.856 422 4 m (for the UK, see).