Roof Slope Calculator
Use this Roof Slope Calculator to estimate volume for the Roof Slope Calculator search intent. Use this roof pitch calculator to convert between rise, run, pitch percentage, roof angle, and rafter length. It is a quick planning tool for gable, shed, and other sloped roofs.
Result
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What This Roof Slope Calculator Helps You Do
Use this roof pitch calculator to convert between rise, run, pitch percentage, roof angle, and rafter length. It is a quick planning tool for gable, shed, and other sloped roofs.
How to Roof Slope Calculator
- Measure the roof pitch inputs - Enter the dimensions, density, spacing, or thickness values shown on the page.
- Check the units - Keep every input in the same unit system so the result stays consistent and easy to compare.
- Choose the solve mode - Select the calculation you want to run, such as weight, volume, cost, count, or angle.
- Read the output - Use the main result and the extra detail rows to verify the estimate before you order materials or build.
Roof Slope Calculator Formula
| Symbol | Definition | Unit |
|---|---|---|
| rise | Vertical rise | ft |
| run | Horizontal run | ft |
| p | Pitch percent | % |
| L | Rafter length | ft |
Working Examples for Roof Slope Calculator
- rise: 1.5
- run: 6
- pitchPercent: 0
- pitchAngle: 0
- pitchRatio: 0
- rafterLength: 0
Result: Roof pitch = 25.00 %
A 1.5 ft rise over a 6 ft run is a common pitch check. The estimate is 25.00 %.
- rise: 2
- run: 8
- pitchPercent: 0
- pitchAngle: 0
- pitchRatio: 0
- rafterLength: 0
Result: Roof angle = 14.04 deg
Angle is the easiest way to compare roof slope with code guidance. The estimate is 14.04 deg.
- rise: 3
- run: 9
- pitchPercent: 0
- pitchAngle: 0
- pitchRatio: 0
- rafterLength: 0
Result: Rafter length = 9.49 ft
Rafter length helps when you are ordering framing lumber. The estimate is 9.49 ft.
- rise: 2.5
- run: 10
- pitchPercent: 0
- pitchAngle: 0
- pitchRatio: 0
- rafterLength: 0
Result: Roof pitch ratio = 3.00 :12
The 12-based ratio is a fast way to talk about pitch on site. The estimate is 3.00 :12.
How to Interpret Your Results
| Range | Meaning | Action |
|---|---|---|
| < 4:12 | Low pitch | Usually needs careful material selection and drainage planning. |
| 4:12–9:12 | Conventional pitch | Common for most houses and sheds. |
| > 9:12 | Steep pitch | Check access, safety, and extra roofing fasteners. |
Frequently Asked Questions About Roof Slope Calculator
Sources
Last reviewed: March 2026