Convert rise over run to pitch (X/12), degrees, percent grade, slope multiplier and recommended waste factor — all instantly.
Vertical distance roof goes up.
Horizontal distance the rise spans. Most contractors use 12.
Visual
Pitch
Walkable with caution
Angle
26.6°
From horizontal
Percent grade
50.0%
Rise ÷ run
Slope multiplier
× 1.118
Footprint → slope length
Recommended waste factor
12%
Industry standard for this pitch
Labor cost adjustment
× 1.08
Vs a flat / low-slope baseline
What is "X over 12"?
Roofers describe pitch as the number of inches a roof rises for every 12 inches of horizontal run. A "6/12 pitch" rises 6 inches vertically for every foot horizontally — that's a 26.6° angle, or 50% grade.
RidgeIQ auto-detects pitch + waste factor from satellite imagery — no climbing required.
| Pitch (X/12) | Degrees | Class | Waste % |
|---|---|---|---|
| 1/12 | 4.8° | Flat / low slope | 8% |
| 2/12 | 9.5° | Low slope | 10% |
| 3/12 | 14.0° | Low slope | 10% |
| 4/12 | 18.4° | Low slope | 10% |
| 5/12 | 22.6° | Conventional | 12% |
| 6/12 | 26.6° | Conventional | 12% |
| 7/12 | 30.3° | Conventional | 12% |
| 8/12 | 33.7° | Steep | 15% |
| 9/12 | 36.9° | Steep | 15% |
| 10/12 | 39.8° | Very steep | 18% |
| 12/12 | 45.0° | Very steep | 18% |
| 14/12 | 49.4° | Extreme | 22% |
The DIY method: place a 12-inch level horizontally against the roof slope. Measure the vertical distance from the level (at the 12-inch mark) straight down to the roof surface. That measurement, over 12, is your pitch. Always use a harness.
Steeper roofs require more cuts at hips and valleys, more starter strips, and have more material slide off during install. Waste factors are a multiplier on the calculated roof area to account for material you'll cut, scrap or replace. We use 10% as the floor and scale up with pitch + complexity.