Acres to square feet area measurement units conversion table shows the most common values for the quick reference. Alternatively, you may use the converters below to convert any other values. 1 Acre = 43 560 Square Feet. Acre is an imperial and U.S. customary system area unit. In metric system, it's replaced by hectare. The abbreviation is ac. Square foot is an imperial and U.S. customary area unit. In metric system, it's replaced by square meters (metres). The abbreviations are sq ft and ft2.