How this worksheet works
One slope, four useful formats
Roof pitch can be expressed as rise over run, degrees, percent grade, or a slope factor. This converter keeps those representations together so plans, field notes, and product instructions can be compared.
How to use it
- Enter rise and run in the same unit.
- Calculate to see the normalized pitch per 12, angle, grade, and area multiplier.
- Use the full-precision values for checking; rounded display values are for practical review.
Useful for
- Converting an inclinometer reading to common pitch language
- Checking pitch-dependent product requirements
- Finding the area multiplier for a takeoff
Assumptions
- Rise and run describe a right triangle
- Both measurements use the same unit
- The roof plane has a constant slope
Limitations
- Does not determine whether a product is approved for a slope
- Field readings can be affected by uneven surfaces
- Rounded pitch labels may not reproduce the exact entered angle
Common checks
Questions about this calculator
Is a 6:12 pitch 45 degrees?
No. A 6:12 pitch is about 26.6 degrees. A 12:12 pitch is 45 degrees.
What does percent grade mean?
Percent grade is rise divided by run, multiplied by 100. A 6:12 pitch is a 50% grade.