Roofing Calculator
Turn a roof's footprint and pitch into roof area, roofing squares and shingle bundles.
Roofing squares (with waste)
14.76
- Shingle bundles
- 45
- Roof area
- 1,341.64 ft²
- Pitch angle
- 26.57°
- Pitch multiplier
- 1.1180
Works for gable and hip roofs with a single pitch. Material counts are estimates — check with your supplier and local code before you buy.
Show the work
Pitch multiplier: sloped roof length per foot of run
m = √(1 + (rise ÷ 12) to the power of 2)
√(1 + (6 ÷ 12) to the power of 2) = 1.118034
Roof area: footprint × pitch multiplier
A = length × width × m
40 × 30 × 1.118034 = 1,341.64 ft²
Squares (100 ft² each), plus waste
squares = A ÷ 100 × (1 + waste ÷ 100)
1,341.64 ÷ 100 × (1 + 10 ÷ 100) = 14.76
How it works
Roof area = footprint × √(1 + (rise ÷ 12)²); squares = area ÷ 100 × (1 + waste); bundles = squares × bundles per square
Questions
- How does the roofing calculator work?
- Roof area = footprint × √(1 + (rise ÷ 12)²); squares = area ÷ 100 × (1 + waste); bundles = squares × bundles per square.
- What do I need to enter?
- Footprint length, Footprint width, Pitch (rise per 12 in), Extra for waste, Bundles per square. Optional fields can be left blank.
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