basic

Roof Pitch Calculator

Pitch ratio, angle, and rafter length from rise and run.

Convert between roof pitch (rise:run), angle in degrees, and rafter length using right-triangle math.

Marcus Laurent By Marcus Laurent
Published Last reviewed 1 min read

Inputs

in or ft
in or ft

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

Angle = arctan(rise / run). Rafter length = √(rise² + run²). Pitch is usually written as rise per 12 inches of run.

In depth

Convert between roof pitch (rise:run), angle in degrees, and rafter length using right-triangle math.