DiyEstim

Roofing Calculator

Estimate roof squares and shingle bundles by roof area and pitch.

Runs locally in your browser — your measurements never leave this page
ft
ft
%

Try: Roof length=30, Roof width=20, Pitch factor=1, Waste=10, Units=ft → 600.00 ft², 1, 6.60, 20

How to use

Enter the roof footprint length and width and the pitch factor (steeper roofs have more surface). One square = 100 ft²; three bundles make a square. The calculator applies both the pitch and a 10% waste margin.

FAQ

What is a roofing square?

A square is 100 ft² of roof surface — the standard unit shingle bundles are sold by (3 bundles per square).

How do I find the pitch factor?

Measure how far the roof rises per 12 inches of run; ×1.0 is low, ×1.15 medium, ×1.3 steep. When unsure, use 1.15.

Does this include the starter and ridge?

No — add one extra bundle for starters and ridge caps beyond the field count.

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