Start by measuring the roof’s length and width in feet as you’re standing on the ground. The calculator above can handle all of this simply enter the length, width, and pitch, and it will determine the size of the roof in squares. While the illustration above shows a simple gable roof, a cross gable roof will require you to take the length and width of each individual section, and complex roofs like gambrels and mansards will have two sections of roofing to each side. Keep in mind that you will need to do this for each section of the roof. To calculate a roof’s dimensions, you need to measure the roof as if it were flat, then account for roof pitch, calculate square footage, and finally determine how many squares of material are required for the roof.
