# square miles to acres

This converter makes instant conversions from square miles (mi²) to acres (ac). It also provides the conversion steps. To use the converter, please provide a value in the input field. The converter will begin making conversions as the values are being typed in.

### How many acres in a square mile?

Both acre and square mile are units of area in the United States (US) customary systems of measurement as well as in the British imperial system. In both systems, an acre is defined to be of a square mile. Based on this, there are 640 acres in a square mile.

### How to convert square miles to acres

Based on the definition of 1 acre being exactly of a square mile, there are 640 acres in a square mile. Therefore, the square mile to acre conversion formula is:

ac = 640 × mi²

Thus, to convert from square miles to acres, multiply a value in square miles by 640. For example, convert a piece of land with size of 0.28 square miles to ac:

0.28 mi² = 0.28 × 640 ac = 179.2 ac