Roofing Calculator
Enter your roof footprint and pitch to get the roof area, roofing squares, and how many bundles of shingles to order.
Roof
Footprint is the ground area the roof covers; pitch scales it up to the actual sloped area.
You'll need
Architectural shingles run ~3 bundles per square. Add starter strip, ridge cap, and underlayment separately.
How to estimate shingles
Multiply the roof footprint by a pitch factor to get the true sloped area, divide by 100 for squares, and multiply squares by 3 for bundles of architectural shingles. Add 10–15% for waste, plus starter, ridge cap, and underlayment.
Measure the whole exterior, not just the roof
ProBuildCalc turns your iPhone's LiDAR scanner into a job-site measuring kit — walk the space and it captures the square footage, material takeoff, and a blueprint automatically. No tape measure, no graph paper.
Roofing calculator FAQ
- What is a roofing square?
- A square is 100 square feet of roof area. Roofers measure and price work in squares — a 2,000 sq ft roof is 20 squares.
- How many bundles of shingles are in a square?
- Most architectural (dimensional) shingles come 3 bundles per square. Heavier or premium shingles can be 4 bundles per square — check the wrapper.
- How do I figure roof area from the footprint?
- Multiply the building's footprint by a pitch factor: about 1.12 for a 6-in-12 roof, 1.25 for 9-in-12, and 1.42 for 12-in-12. The calculator applies this for you.
- How much waste should I add for roofing?
- Add about 10% for a simple gable roof and 15% for roofs with hips, valleys, and dormers that need more cutting.