The square mile is an imperial and US unit of area equal the area of a square of one statute mile. It should not be confused with miles square, which refers to the number of miles on each side squared. For instance, 20 miles square (20×20 miles) is equal to 400 square miles.

Conversions

• 4,014,489,600 square inches
• 27,878,400 square feet
• 3,097,600 square yards
• 640 acres
• 2560 roods
• 25,899,881,103.36 square centimeters
• 2,589,988.110336 square meters
• 2.589988110336 square kilometers

In the Public Land Survey System of the U.S. and the Dominion Land Survey of Canada, the size of a standard section of land is one square mile, but always with the marginally larger survey definition.