Acres to Square miles converter

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

1 ac = 0.0015625 mi²
1 mi² = 640 ac

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

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

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.

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.

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