Measure first
Measure finished dimensions, actual stock, openings, and site constraints before ordering material.
Roof planning
Roof Pitch Calculator: rise, run, angle, and rafter length
Enter the vertical rise over a horizontal run to convert a roof slope into the familiar pitch format, degrees, slope percentage, and an approximate common-rafter length.
How the estimate works
Use the number as a planning starting point.
Pitch is rise per 12 inches of run. The angle uses arctangent(rise/run), while the rafter length uses the Pythagorean theorem on the horizontal run plus overhang.
Check the result
Roof geometry is useful for early material planning, but it does not verify loads, wind, snow, connections, species, or local code. Confirm all structural details before cutting or building.
Plan the next step
Use the related calculators below to turn a first estimate into a material list, layout, or a more detailed project plan.
FAQ
Common Roof Pitch Calculator questions
What does a 6:12 roof pitch mean?
It means the roof rises 6 inches for every 12 inches of horizontal run.
Is roof pitch the same as roof angle?
No. Pitch is a ratio; angle expresses the same slope in degrees. This calculator shows both.
Related tools
Keep the project moving.
Rafter Length Calculator
Free rafter length calculator. Estimate a common-rafter diagonal length from roof rise, run, and overhang for early roof planning.
Open Rafter Length CalculatorRoof Shingle Calculator
Free roof shingle calculator. Estimate roof area, roofing squares, shingle bundles, and waste allowance from building size and roof pitch.
Open Roof Shingle CalculatorStair Angle Calculator
Free stair angle calculator. Convert stair rise and run into degrees, slope percentage, pitch ratio, and approximate stringer length.
Open Stair Angle CalculatorPlanning disclaimer: WoodCutTool results are estimates. Verify measurements, product instructions, material condition, local requirements, and safety practices before buying, cutting, or building.