Square miles to Acres converter

To convert square miles to acres, enter the value in the first field. The result in acres is calculated automatically using the exact conversion factor.

1 mi² = 640 ac
1 ac = 0.0015625 mi²

Formula: ac = mi² × 640
mi² = ac × 0.0015625

Definitions: 1 mi² = 640 ac; 1 ac = 43560 ft²

The square mile (mi²) is 640 acres, about 2.59 square kilometers. It is used for the area of cities, counties, states and countries in the United States and the United Kingdom.

The acre (ac) is 43,560 square feet, about 4,047 square meters or 0.4047 hectares. It is used for land area in the United States and, informally, in the United Kingdom and Canada, and traditionally it was the area a team of oxen could plow in a day.

See the conversion table with commonly used values, handy for quick reference or study.