Roof pitch calculator: pitch, angle and rafter factor
By the Hewer team · · 1 min read
Roofers, framers and gutter installers all need the pitch, and they get it in different forms: a level and a tape, a degree reading, or a set of plans. Roof Slope takes any of them and gives you the rest.
What Roof Slope works out
- The pitch as rise over 12.
- The angle in degrees.
- The multiplier for turning a flat run into rafter length or sloped roof area.
- A drawing of the slope.
How to use it
- Pick how you measured: Rise/12, Degrees, Rise/run, or Phone.
- For Rise/12, hold a level flat against the roof, mark 12 inches out along it, and measure straight down to the roof.
- For Phone, lay the phone on the roof or rafter and let it read the angle.
- Read the pitch, angle and multiplier at the top.
Tips from the field
- Multiply a plan-view area by the multiplier to get the real roof area for ordering material.
- Measure on a rafter or the roof deck, not on shingles that might be bowed.
- For material counts, carry the pitch into Roof Material.
Free, and no account needed
The Hewer Trade Toolkit is free. It runs in any phone browser, saves your last inputs, works in feet and inches or metric, and keeps layouts in job folders you can export as a PDF. If you run a crew, the same calculators are inside Hewer's crew app, next to the jobs, the schedule and the clock-in.
Questions
What does a 6/12 pitch mean?
The roof rises 6 inches for every 12 inches it runs horizontally. That's about 26.6 degrees.
Can I measure pitch with my phone?
Yes. Choose Phone, lay it on the roof or a rafter, and the tool reads the angle from the phone's motion sensor.
