A quarter mile by quarter mile is a square area measuring 0.25 miles on each side. To calculate the area in acres, first convert the dimensions to feet (1 quarter mile = 1,320 feet). The area is then 1,320 feet x 1,320 feet, which equals 1,742,400 square feet. Since 1 acre is 43,560 square feet, this area is approximately 40 acres.