Convert acres to square miles
Enter a acres value below and convert to square miles
ac
1 acre ≈
0.001563 square miles
* rounded result
Select how many decimal places the result will be rounded to:
How to convert acres to square miles
To convert acres to square miles, divide a acres value by 640.
Formula mi² = ac / 640
Example: Convert 100 acres to square miles Calculations: 100 ac / 640 ≈ 0.1563 mi²
Acre (ac)
The acre is the imperial system's unit of area, defined as the area of a rectangle with sides of 66 and 660 feet. It is equal to about 0.4047 hectares.
Square mile (mi²)
The square mile is the imperial system's unit of area, defined as the area of a square with sides of 1 mile. It is equal to about 2.59 square kilometers.