Roof Pitch Calculator

Enter the rise, run, and rafter length of a roof to calculate the the roof pitch angle and percentage.

Roof Pitch Formula

In short, a roof can be visualized as a triangle, therefore it’s numerical values can be calculated through the Pythagorean theorem.

rafter² = rise² + run²

  • Where rise and run are the height and length of the roof.

rise / run = pitch, where pitch is expressed in percent

  • Where pitch is the angle between the ground and the rafters.
roof pitch calculator