Acre (ac)

Definition

Exactly 43 560 square feet (4046.8564224 m²).

History

The acre began as the area a yoke of oxen could plough in a day, later fixed as 43 560 square feet, or one furlong by one chain. It equals about 4047 square meters.

Where it is used

Acres are the customary measure for land, farm plots and larger properties in the United States and United Kingdom.

Typical uses include land and farm plots, US real estate.

Conversion pages

These pages convert acre to or from another unit in area.

• Acre to hectare
• Square foot to acre

Other Area units

• Square meter (m²)
• Square foot (ft²)
• Square inch (in²)
• Square centimeter (cm²)
• Square kilometer (km²)
• Square mile (mi²)
• Hectare (ha)
• Square yard (yd²)

Sources

• NIST HB 44 NIST Handbook 44, Appendix C (area); 1959 yard-and-pound agreement · Dataset reviewed Nov 11, 2026