Free tool
Roof Pitch Calculator: Pitch, Angle and Slope
Rise and run to pitch, angle, slope and pitch factor, both ways.
This roof pitch calculator turns a rise and a run into a roof pitch, an angle in degrees and a pitch factor. Measure how many inches the roof rises over 12 inches of level run and type it in. It works the other way too: enter an angle and it gives you the pitch. Roofers use the pitch to work out how much roof surface there is, how many squares to order, and which roofing products are allowed.
Roof pitch calculator
Your roof pitch
6/12
Never climb a roof to measure pitch. Measure from inside the attic on a rafter, or from a ladder at the gable end.
What roof pitch means
Roof pitch is how many inches a roof rises for every 12 inches it runs level. A 6/12 roof climbs 6 inches over each foot. You will also see it written as an angle (6/12 is about 26.6 degrees) or as a percent slope (6/12 is 50 percent).
Common roof pitches
| Pitch | Angle | Pitch factor | Where you see it |
|---|---|---|---|
| 2/12 | 9.5° | 1.014 | Porches, additions, low-slope roofs |
| 4/12 | 18.4° | 1.054 | Ranch homes, garages |
| 6/12 | 26.6° | 1.118 | Most Minot ranch and split-level homes |
| 8/12 | 33.7° | 1.202 | Two-story homes, newer builds |
| 10/12 | 39.8° | 1.302 | Steep gables, older homes |
| 12/12 | 45° | 1.414 | A-frames, very steep roofs |
Swipe the table sideways to see every column.
How to measure roof pitch safely
- Go into the attic, or stand on a ladder at the gable end.
- Hold a level flat against the underside of a rafter, or out from the roof edge.
- Mark 12 inches along the level.
- At the 12 inch mark, measure straight up to the rafter or roof. That number is your rise.
A phone level app laid on the rafter gives you the angle directly. Type it into the angle box above.
Why pitch matters for your roof
Material: asphalt shingles are allowed down to 2/12, but below 4/12 they need extra underlayment. Flatter roofs need a membrane such as TPO or EPDM, which is what we install on commercial and low-slope roofs.
Snow: steeper roofs shed snow better. Low-slope roofs in Minot hold snow longer, which matters for both load and ice dams.
Cost: the pitch factor sets how much roof surface you are paying for, and very steep roofs need extra safety setup. Take your pitch to the shingle and roof square calculator to count squares, then to the roof replacement cost calculator for a price.
More free roofing tools
Want the exact number?
Free inspection, photo report the same day, written line-item quote.