Roof Pitch Calculator
Convert between rise/run, slope angle, and standard pitch labels
About this calculator
The Roof Pitch Calculator converts between rise/run measurements, slope angle in degrees, and the standard US pitch label (rise per 12 of run). From rise and run it also returns the percent grade and rafter (hypotenuse) length; from an angle it derives the equivalent pitch label and grade. Every result is categorized as flat, low, conventional, or steep, and non-positive inputs or angles outside 0–90° return an error.
How to use the Roof Pitch Calculator calculator
- Enter your values into the input fields.
- Read the result — it updates instantly as you type.
- Adjust the inputs to compare scenarios.
- Copy the page URL to share the exact calculation.
Common examples
- Rise 6, run 12 → 6.00/12 pitch, 26.57° angle, 50% grade, rafter length 13.42 (conventional)
- Rise 4, run 12 → 4.00/12, 18.43°, 33.33% grade — low end of conventional
- 30° angle → 6.93/12 pitch, 57.74% grade
- Rise 9, run 12 → 9.00/12, 36.87°, 75% grade — steep
Frequently asked questions
How does the Roof Pitch Calculator calculator work?
Enter your numbers and the calculator applies the standard formula for this everyday task, showing the result and how it was reached. It handles the unit and rounding details so you do not have to.
When would I use the Roof Pitch Calculator calculator?
Whenever this comes up in daily life — planning, shopping, home projects, travel or work — and you want a quick, dependable answer instead of estimating or working it out by hand.
How accurate are the results?
The math runs at full precision internally and only the displayed value is rounded for readability. For real-world use the practical limit is the accuracy of the numbers you enter, not the calculation.
Can I share a specific calculation with someone else?
Yes. Every value you enter updates the URL, so copying the address bar and sharing the link reopens the exact same calculation for whoever clicks it.