Roof Pitch Calculator

Convert a roof's rise and run into its angle, slope percentage, and traditional "X-in-12" pitch notation.

  • Free to use
  • Accurate results
  • No registration required
  • Works on all devices
Enter your roof's rise and run to find its angle, slope percentage, and traditional X-in-12 pitch notation.
Vertical height gained — any consistent unit works (meters or feet), since this is a ratio calculation.
Horizontal distance covered, in the same unit as rise.

Your result

26.57

Angle

Slope percentage50
Pitch (X-in-12 notation)6 in 12

AI explanation

Formula

Angle = arctan(rise ÷ run); slope % = (rise ÷ run) × 100; pitch = (rise ÷ run) × 12, in 12

Worked example

1:2 rise:run

Worked example: 1:2 rise:run
FieldValue
Rise1
Run2
Angle26.57
Slope percentage50
Pitch (X-in-12 notation)6 in 12

Assumptions

  • Rise and run must be entered in the same unit — the result is a ratio, so it works whether you use meters, feet, or any other consistent unit.

Frequently asked questions

What does "6 in 12" pitch mean?

It means the roof rises 6 units for every 12 units of horizontal run — a traditional construction notation (also written "6/12" or "6:12") that's unit-independent.

What roof angle is considered "steep"?

Roofs above about 45° (a 12-in-12 pitch) are generally considered steep; most residential roofs fall between 15° and 40°.

How do I find the actual roof surface area from the pitch?

Use the Roofing Calculator, which takes the footprint area and slope angle to compute the actual sloped surface area needed for material ordering.

Related calculators

Report a calculation issue