A square is a figure with four equal length sides, and the perimeter of a square is the total distance around the outside of the shape. Calculate the perimeter by adding all four sides together. The area of a square is the amount of surface the shape covers and is measured in square units. You can calculate the area of a square by using both the length of one side and its perimeter.

Divide the perimeter length by 4 to get the measurement for each side of the square. For example, a square with a perimeter of 20 inches has four sides of five inches each.

Multiply the length of one side by another side. With a square, because all sides are equal, you are essentially squaring the side. Multiplying 5 times 5 equals 25 in our example.

Convert the measurement to square units. Keep the units static across the board. If you use inches for the perimeter, the area is in square inches.