Roof Pitch Calculator

How to calculate roof pitch

1. Enter the rise and run, or the angle.
2. Add the footprint area to get the roof area, or a rafter's horizontal run to get its length.
3. See the pitch, angle, slope and multiplier.

Frequently asked questions

What does 6/12 mean?

The roof rises 6 units for every 12 units across. That is a 26.57° angle and a 50% slope.

How do I convert pitch to degrees?

Angle = arctan(rise / run). 4/12 is 18.43° and 12/12 is 45°.

What is the pitch multiplier?

The factor that turns the flat footprint into the sloped roof area: √(rise² + run²) / run. For 6/12 it is about 1.118.