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Roofing Calculator
Roof squares and shingle bundles — footprint and pitch in, squares and bundles out.
Squares to order
How it works
Roof area = footprint ÷ cos(pitch) Squares = roof area ÷ 100 sq ft Bundles = squares ordered × 3 Example: 100 m² at 30° → 12.43 squares
Worked example: a 100 m² footprint at a 30° pitch has a roof area of 100 ÷ cos(30°) = 115.47 m², which is 1,242.9 sq ft, or 12.43 squares. Rounded up, order 13 squares, which is 13 × 3 = 39 bundles.
Frequently asked questions
What is a roofing square?
One square is 100 square feet of roof area. Roofing materials are commonly priced and ordered by the square.
How do I measure the pitch?
Pitch here is the angle of the roof in degrees. A flat roof is 0° and a steep roof can reach 45° or more.
Are bundles always 3 per square?
Three bundles per square is the common figure for asphalt shingles, but it varies by product. Check the pack for the product you plan to buy.
Does this include waste?
No. Hips, valleys and ridges need extra material, so allow roughly 10% more on a complex roof.
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