Sloped roof area
Convert a roof footprint and pitch to covering area.
How this works
Expand the footprint by the overhang, then multiply by √(1 + (rise/12)²).
Example
Using the example inputs, covering area with allowance is 1,652.901449 ft².
- Footprint length
- 40 ft
- Footprint width
- 30 ft
- Overhang on each side
- 1 ft
- Rise per 12 inches run
- 6 in
- Extra allowance
- 10 %
- Covering area with allowance
- 1,652.901449 ft²
Scope and assumptions
Quantity/geometry estimate only. Not structural design, building-code approval, or installation instructions.
OpenStax mathematics reference