One roofing square equals 100 square feet of roof surface, so to find how many squares your roof is, divide the total roof area (not the ground footprint) by 100. A roof with 2,400 square feet of surface is 24 squares. The catch: you need the actual sloped surface area, which depends on pitch, not the flat footprint.
What is a roofing square?
A "square" is the roofing industry's unit for quantifying material. One square covers 100 square feet. Shingles, underlayment, and labor are all estimated in squares, so an accurate square count is the foundation of an accurate estimate.
Why footprint area is not enough
The flat outline of a house (its footprint) understates the real roof area because a pitched roof is longer along the slope than across the ground. A steeper pitch means more surface area per square foot of footprint. That is why a roof measurement report gives per-facet surface areas and the pitch of every facet, so the square count reflects the real roof.
How to convert area to squares
- Add up the surface area of every roof facet in square feet.
- Divide the total by 100 to get squares.
- Add a waste factor (commonly 5 to 15%) for cuts, hips, and valleys.
A roof measurement report does the first two steps for you and includes waste factor tables at 0%, 5%, 10%, 15%, and 20%.
Get an exact square count from an address
Instead of estimating from the ground, RoofAngle measures every facet from aerial imagery and reports total area and squares. Enter an address to get an exact count, delivered as ESX or XML from $17.