Construction
Roof Pitch Angle Calculator
Turn roof rise and run into a pitch angle in degrees and a pitch ratio.
The result is the steepness of the roof as an angle in degrees, together with the rise-in-run pitch, so a larger angle means a steeper roof.
Formula
Pitch angle = arctangent of (rise divided by run), converted from radians to degrees.
How it works
Enter the vertical rise and the horizontal run over the same section of roof, in any matching units. The angle helps with material choice, since very shallow pitches suit different coverings than steep ones. Always measure rise and run over the same roof section.
Worked example
For example, arctangent(2 ÷ 4) = 26.6 degrees, which is a 2 in 4 pitch.
FAQs
What units can I use?
Any matching pair, such as metres and metres or feet and feet. Mixing units gives a wrong angle.
What is a steep pitch?
Above about 45 degrees is steep and harder to work on, while below about 15 degrees is shallow and needs careful waterproofing.
Does pitch decide the roofing material?
Partly. Each material has a minimum pitch, so check the manufacturer's guidance before choosing.
Rough estimate only — consult a licensed professional for structural work before building.
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