Why use this tool?
Roof pitch determines everything from material choices to how steep a roof feels to walk on. Enter your rise and run, and this tool converts it into the pitch ratio, angle, and an estimated rafter length for planning.
How it works
- Enter the rise — how many inches the roof climbs over a 12-inch run.
- Optionally enter your building's width to estimate rafter length.
- Read off the pitch ratio, angle, and slope factor.
Frequently asked questions
What does '6/12 pitch' mean?It means the roof rises 6 inches for every 12 inches of horizontal run — a common residential pitch.
Is the rafter length exact?It's a planning estimate based on rise, run, and building width. Always confirm exact measurements with a contractor before ordering materials.
Does this account for overhang?Yes, there's an optional overhang field that adds to the estimated rafter length.