acres to square miles
This converter makes instant conversions from acres (ac) to square miles (mi²). 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 square miles in an acre?
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 = 0.0015625 square miles in an acre.
How to convert acres to square miles
Based on the definition of 1 acre being exactly of a square mile, there are 640 acres in a square mile. Therefore, the acre to square mile conversion formula is:
mi² = 

Thus, to convert from acres to square mile, divide a value in acres by 640. For example, convert a park of 300 acres to square miles:
300 ac = 

mi² = 0.46875 mi² 