Roof Pitch Calculator

Calculate roof pitch, slope percentage, angle, and rafter length from rise and run.

Enter your values, then select the button.
Roof Pitch Calculator method
Angle = arctan(rise ÷ run).

How to use the roof pitch calculator

  1. Rise: Vertical rise using the same unit as the run.
  2. Run: Horizontal run from wall to ridge.
  3. Select the button and review the result.

Worked example

A 6 rise over 12 run is a 6:12 pitch, 50% slope, and about 26.57° angle.

Method and limitations

Angle = arctan(rise ÷ run).

Geometry estimate only. Roofing work requires safe measurement and local professional guidance.

Common questions

Why might another result be different?

Inputs, rounding, policies, rates, and assumptions can differ. Compare like-for-like values and use current official information when a rate or rule can change.

Does NidXee save my entries?

No. The calculation runs in your browser. Reloading or closing the page may clear it.