Roof Pitch Calculator
Converts between pitch notation (6/12), degrees, percentage slope, and rise-run ratios. Quick reference for any roof pitch format.
Conversions
Common Pitch Reference
| Pitch | Degrees | Slope % | Factor | Class |
|---|---|---|---|---|
| 2/12 | 9.5° | 16.7% | 1.0138 | Nearly flat |
| 3/12 | 14.0° | 25.0% | 1.0308 | Low slope |
| 4/12 | 18.4° | 33.3% | 1.0541 | Standard low |
| 5/12 | 22.6° | 41.7% | 1.0833 | Moderate |
| 6/12 | 26.6° | 50.0% | 1.1180 | Standard |
| 7/12 | 30.3° | 58.3% | 1.1577 | Moderate steep |
| 8/12 | 33.7° | 66.7% | 1.2019 | Steep |
| 10/12 | 39.8° | 83.3% | 1.3017 | Very steep |
| 12/12 | 45.0° | 100.0% | 1.4142 | 45 degrees |
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How to Use This Calculator
1. Choose your input format. If you know the pitch (like 6/12), enter the rise. If you measured the angle with a tool, enter degrees. If you have a percentage from a survey, enter the slope percentage.
2. Enter the value. The calculator instantly converts to all other formats. It also shows the pitch correction factor used for area calculations and a steepness classification.
3. Use the reference table. The quick reference shows all common pitches with their conversions for easy comparison.
How Pitch Conversion Works
Roof pitch, degrees, and slope percentage are three ways to describe the same angle. The calculator uses standard trigonometry to convert between them.
Degrees = arctan(Rise / 12) x (180 / pi)
Slope_Pct = (Rise / 12) x 100
Pitch_Factor = sqrt((Rise^2 + 144) / 144)
Rise (from degrees) = 12 x tan(Degrees x pi / 180)
Rise (from %) = Percentage x 12 / 100
The pitch factor is particularly useful because it converts flat footprint area to actual sloped roof area. A 6/12 pitch has a factor of 1.118 — meaning the sloped area is about 11.8% larger than the footprint.
Frequently Asked Questions
How do I convert roof pitch to degrees?
What does 6/12 roof pitch mean?
What is a walkable roof pitch?
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