Measure rise and run
From a level 12-inch run, measure the vertical rise. A 6-inch rise is a 6/12 pitch. You can also start from degrees or percent.
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Roof Pitch Calculator
Convert rise and run into an X:12 pitch, degrees, slope percent, a pitch multiplier, and rafter length. Results update as you type.
- One triangle on one screen
- Live diagram and formulas
- Carry the pitch into the roofing calculator
Convert rise and run
Results update as you type. Nothing is stored on a server.
Measurements stay in your browser
How to calculate roof pitch
Pitch, slope, angle, and gradient are the same triangle in different units. This page keeps them in one place.
Convert the triangle
Degrees = arctan(rise ÷ run). Percent = rise ÷ run × 100. The multiplier is √(1 + (rise ÷ run)²).
Use it on the roof area
Multiply the building footprint by the pitch multiplier to estimate sloped roof area, then continue to squares and shingles.
Roof pitch calculator FAQ
These answers cover the conversions people search as slope, angle, and gradient calculators.
How do I calculate roof pitch?
Measure the vertical rise over a 12-inch horizontal run. If the roof rises 6 inches in those 12 inches, the pitch is 6/12. This calculator also converts that ratio into degrees, percent slope, and a pitch multiplier.
What is a 6/12 roof pitch?
A 6/12 pitch rises 6 inches for every 12 inches of run. That is about 26.6 degrees, a 50% slope, and a 1.118 pitch multiplier. It is a common conventional residential pitch in the United States.
How do I convert roof pitch to degrees?
Degrees = arctangent(rise ÷ run) × 180 ÷ π. A 6/12 pitch is arctangent(0.5), which is 26.6 degrees. You can also enter degrees here and get the equivalent X:12 ratio.
What is a pitch multiplier?
The pitch multiplier converts a horizontal footprint into sloped roof area: multiplier = √(1 + (rise ÷ run)²). Multiply the building’s projected area by this factor to estimate actual roof surface.
Is roof pitch the same as roof slope or roof gradient?
They describe the same geometry in different units. Pitch is usually X-in-12, slope is often a percentage, and gradient or angle is degrees. This page keeps all three in sync so you do not need separate calculators.
What counts as a low, conventional, or steep slope?
This tool labels under 2/12 as flat, 2/12 to under 4/12 as low slope, 4/12 through 9/12 as conventional, and above 9/12 as steep. Manufacturer and code limits still govern which materials you can install.