Question: 1 square mile is how many miles?
Answer: For instance, 20 miles square (20 × 20 miles) has an area equal to 400 square miles; a rectangle of 10 × 40 miles likewise has an area of 400 square miles, but it is not 20 miles square. One square mile is equal to: 4,014,489,600 square inches. 27,878,400 square feet.