Things You'll Need:
- Ladder
- Tape measure
- Pen and paper
- Calculator
-
Step 1
Measure a simple gable roof from end to end and from the peak to the eave. Multiply the two numbers together for square feet and multiply by two to include both sides of the roof.
-
Step 2
Measure other roofs as triangles and rectangles. Calculate the area of each triangle and rectangle and add it to the total roof area. Measure from peak to eave, eave length and peak length.
-
Step 3
Multiply 1/2 by the base of the triangle, then multiply by height for the area of a triangular section. Multiply length by width for the area of a rectangle.
-
Step 4
Multiply calculated areas by two if there are two identical areas. Total all areas and round the number up to the nearest 100 square feet. For example 1,442 square feet rounds up to 1,500 square feet. Divide the rounded up number by 100, for the number of "squares."
-
Step 5
Divide the number of squares by the number of shingle bundles per square. Round this number up to an even number. Add 1 percent to the number of bundles for a simple roof, add 5 percent for hip roofs and up to 7 percent for more complicated roofs.
