Roofing Calculator
Convert a simple building footprint and rise-per-12 pitch into sloped roof area, then add waste and estimate roofing squares and bundles.
Roof area with waste1,578 ft²
Roofing squares15.78
Shingle bundles48
Pitch factor1.118
This models a simple symmetrical pitched roof from plan dimensions. Valleys, hips, dormers and complex roof geometry need separate surface measurements.
How this tool works
Sloped area = plan area × √(1 + (rise/12)²). One roofing square is 100 ft².
Example
A 6:12 pitch has a slope factor of about 1.118, so its sloped area is roughly 11.8% larger than horizontal plan area.
Common questions
Does this handle hips, valleys and dormers?
Not explicitly. Complex roofs should be broken into measured roof planes and waste adjusted for geometry.
What is a roofing square?
A roofing square is 100 square feet of roof surface area.