Acre (ac)
The acre is a US and imperial unit of land area: 43 560 square feet, or about 4 046.86 m² (0.4047 ha).
Symbol: ac
Quantity: area
SI relation: 1 ac = 4046.8564224 m² (exact)
Derivation: 1 acre = 43 560 ft² = 4 046.856 422 4 m² (international foot; the US survey foot was retired at the end of 2022)
Exact: yes, by definition
Typical uses
- US, UK and Indian land and property listings
- Farm and ranch area
- Park and campus sizes
Convert acres to other units
| Conversion | 1 ac equals | Reverse |
|---|---|---|
| acre to square meter | 4046.856422 m² | square meter to acre |
| acre to square centimeter | 40468564.22 cm² | square centimeter to acre |
| acre to square foot | 43560 ft² | square foot to acre |
| acre to square inch | 6272640 in² | square inch to acre |
| acre to hectare | 0.4046856422 ha | hectare to acre |
| acre to square millimeter | 4046856422 mm² | square millimeter to acre |
| acre to square kilometre | 0.004046856422 km² | square kilometre to acre |
| acre to square yard | 4840 yd² | square yard to acre |
| acre to square mile | 0.0015625 mi² | square mile to acre |
Open the Area Converter to convert any value between all units.
Sources
- NIST Handbook 44, Appendix C: General Tables of Units of Measurement, National Institute of Standards and Technology , Appendix C, units of area.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Acre (ac). Retrieved October 25, 2026, from https://scientificconverters.com/units/acre/
IEEE
Scientific Converters, "Acre (ac)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/units/acre/