Square mile

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:
 * 4,014,489,600 square inches
 * 1 mi2
 * 1 mi2
 * 1 mi2
 * 1 mi2

One square mile is also equivalent to:
 * 1 mi2
 * 1 mi2
 * 1 mi2

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 ($4.015 sq in$ × $2.788 ft2$) has an area of $3.098 yd2$; a rectangle of measuring $640 acres$ × $2.59 m2$ also has an area of $2.59 km2$, but is not 20 miles square.

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