The
square mile (abbreviated as
sq mi and sometimes as
mi2) is an
imperial and
US unit of measure for an
area equal to 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; an area of 10 × 40 miles is likewise 400 square miles, but it is not 20 miles square.