Calculate roof pitch as X:12, the angle in degrees, and the area multiplier to convert your floor plan area to true sloped roof area for shingle and material estimates.
How it works
- Measure and enter the vertical rise in inches.
- Measure and enter the horizontal run (usually 12 inches).
- Provide an optional horizontal plan area to get the true slanted roof surface area.
Frequently asked questions
What pitch is most common?
Residential roofs typically run 4:12 to 9:12, with 6:12 being very common. Low-slope commercial is often 2:12 or less.
Why does pitch matter for shingles?
Low-slope roofs need special materials. Standard asphalt shingles require at least a 2:12 pitch.
How do I measure existing roof pitch?
Place a level on the roof deck, measure 12 inches horizontally, then measure the vertical rise at that point.