The square mile (abbreviated as sq mi and sometimes as mi2) is an imperial and US unit of measure for area. One square mile is equal to the area of a square with each side measuring a length of one mile.

Equivalents

One square mile is equal to: One square mile is also equivalent to:

Similarly named units

Miles square

Square miles should not be confused with miles square, a square region with each side having a length of the value given. For example, a region which is 20 miles square (20 miles × 20 miles) has an area of 400 mi2; a rectangle of measuring 10 miles × 40 miles also has an area of 400 mi2, but is not 20 miles square.

Section

In the United States Public Land Survey System, "square mile" is an informal synonym for section.