Roofing Calculator
Estimate roof area, shingle bundles, and ridge length for gable and hip roofs.
Roofing Estimate
Add 10-15% extra for waste and starter strips. Consult a roofer for precise estimates.
What is the Roofing Calculator?
The Roofing Calculator estimates the surface area of a roof, the number of roofing squares, shingle bundles needed, and ridge length based on building footprint dimensions and roof pitch.
How to Use
- Select the Gable Roof or Hip Roof tab.
- Enter the building length, width, and roof pitch (rise in inches per 12 inches of run).
- Click Calculate to see area, squares, bundles, and ridge length.
Frequently Asked Questions
What is a roofing square?
A roofing square is 100 square feet of roof area. It is the standard unit roofers use to estimate material quantities.
How many bundles per square?
Most standard asphalt shingles require three bundles to cover one square (100 sq ft).
How does pitch affect area?
Steeper roofs have a larger surface area than the building footprint. The calculator uses the pitch factor sqrt(1 + (pitch/12)^2) to account for this.
Should I add extra for waste?
Yes. It is standard practice to add 10-15% extra material to account for cutting waste, starter strips, and future repairs.