Roof Estimating Formulas

The following tools estimate the area of a roof as well as the amount of materials necessary to construct a roof of a given area.

Roof estimating formulas.

The house base area is the area of land that the house covers and for more complex shapes can be estimated using the area calculator. This is because a steep sloped roof requires a taller chimney and more lumber for framing. The roof area is simply 114x18x2 plus 30x18x2 giving 5184 square feet which is perfectly adequate for estimating materials. Since it takes 3 bundles of shingles to cover a square plan to purchase 3 bundles for each square.

However the end result may be well worth it as your roofing material is estimated to last up to 50 longer and will require less maintenance. To estimate roofing materials start by finding the total square footage of the roof and divide the number by 100 to determine the number of squares in the roof. Add overhangs if you have overhangs on the front back and sides of your house you most likely do take the width of the overhang multiply it by 2 and add to each side. The roof area for a hip end is the same as for a gable end the intersection is equivalent to a hip slightly conservative so there is usually no need to consider triangles when measuring a roof.