Roofing Calculator
Estimate roofing squares and shingle bundles needed from roof dimensions.
Roofing materials are sold by the "square" (100 square feet), and a sloped roof has more actual surface area than its footprint suggests — this estimates both from your roof's dimensions and pitch.
Why pitch matters so much
A steeper roof has significantly more actual surface area than a flat footprint of the same width and length — the pitch multiplier accounts for that extra surface created by the slope, which is why a steep roof needs noticeably more material than its ground-level dimensions alone would suggest.
Frequently asked questions
How many shingle bundles come in a "square"?
Typically 3 bundles per square, though this can vary slightly by shingle brand and style — check your specific product's coverage rating.
Should I order extra roofing material for waste?
Most roofing estimates add 10-15% extra for waste, cuts around edges and features, and future repairs.