Free Tools
Roof Pitch Calculator
Figure out your roof pitch as a ratio, angle in degrees, and grade percent. Useful for ordering material, sizing ladders, or checking if a given roofing product will work on your slope.
Measurements
How many inches the roof rises vertically.
Horizontal distance. Defaults to 12 inches for a standard pitch ratio.
Results
This is the sweet spot for Seattle homes. Asphalt shingles, architectural shingles, and metal all work here. Water sheds cleanly, and most contractors are comfortable walking this pitch.
How pitch is measured
Roof pitch is the rise in inches for every 12 inches of horizontal run. A 6:12 pitch means the roof rises 6 inches for every foot you travel horizontally. That works out to about 26.57 degrees and a 50% grade.
If you already have an angle, you can flip the calculator to convert back to a rise over 12 inches of run.
Why it matters in the PNW
Seattle rain is relentless, so pitch drives material choice more than it does in drier climates. Low slopes need membrane systems like TPO. Conventional pitches work with asphalt and metal. Steep roofs handle cedar shake well and shed water and moss faster, which matters a lot around here.
Not sure what your pitch is?
We'll measure it for you during a free roof inspection and tell you what materials make sense for your slope and the PNW weather.