Estimate how much it will cost to roof for your house using this safe DIY tool without having to climb on the roof. Works with a new roof, re-roof, shingles, or metal.

Instructions for the Shingle Calculator

Enter the approximate value for how many square feet the house has in the first number box.

Select how steep the roof is. A 4/12 pitch is relatively easy to walk, an 8/12 is very difficult to walk, and a 12/12 is impossible to walk.

Select the complexity of the roof. One roof line is simple, two to four roof lines is average, and anything over four roof lines is complex.

Choose whether or not your roof is new or will have multiple layers to remove.

Finally, choose what type of new roofing will be used.

This calculator is only an estimation. It is not as accurate as measuring each roof plane and adding the square feet together. It does take into account for an average number of offsets and an overhang. It also takes into account for the starters, the edges, and the ride caps. The squares returned include everything.

The formula for solving for the area of a roof involves climbing onto the roof. Measure each roof plane. For shapes such as trapezoids, triangles, and trapeziums, find the average length by finding the center of the width. Remember to add two feet for valleys. Add the square footage of all of the roof planes together. Divide this by one hundred for the number of squares. There are three bundles of shingles for each square.

To determine how many will be needed for starters and edges, measure the entire perimeter of the roof and divide it by three. Since there are twenty six shingles in a bundle of twenty year shingles (which is fine for starters and edges), divide the result by twenty six.

For the number of ridge caps, multiply the length of the hip or ridge by twelve and divide it by five.

This house is 1000 square feet. It requires 18 squares of shingles. The calculator returns 19. That is because it is so simple.