The square mile (abbreviated as sq mi and sometimes as mi2)Rowlett, Russ (September 1, 2004). "S", How Many? A Dictionary of Units of Measurement. University of North Carolina at Chapel Hill. Retrieved February 22, 2012. 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: about four billion square inches nearly 27.9 million square feet nearly 3.1 million square yards 2,560 roods 640 acres
One square mile is also equivalent to: nearly 2.59 million square meters nearly 25.9 billion square centimeters nearly 2.59 trillion square millimeters
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 ( × ) has an area of ; a rectangle of measuring × also has an area of , but is not 20 miles square.
Section In the United States Public Land Survey System, "square mile" is an informal synonym for section.
References
Formula Conversion, Square miles to numerous area units with algebraic steps and unit cancellation shown