Calculating the Square Footage of a Living Area
Measure the length and the width of the room. The square footage of a square or rectangular living area is calculated by multiplying these two measurements. For example, a room nine feet in length and six feet in width is 36 square feet.
Measure the base and the height or a triangular shaped living space to calculate the square footage. Multiply half the length of the base by the height. For example, an eight feet long by six feet high triangle is 24 square feet.
Measure the square footage of a circular shaped area by measuring the radius, the length from the center of the room to the outer perimeter. Square this number, that is, multiply it by itself. Then multiply this number by pi, or 3.14. For example, a room with a radius of four feet is (4 x 4 x 3.14 =) 50.24 square feet.