Pitch describes how steep a roof is: rise over run. A "6/12" roof rises 6 inches for every 12 inches it runs horizontally. Pitch matters because a steeper roof has more surface area than the same house under a flat roof — and because steep work is slower, harder work.
Pitch multipliers (surface area)
| Pitch | Angle | Surface multiplier |
|---|---|---|
| 3/12 | 14.0° | × 1.031 |
| 4/12 | 18.4° | × 1.054 |
| 5/12 | 22.6° | × 1.083 |
| 6/12 | 26.6° | × 1.118 |
| 7/12 | 30.3° | × 1.158 |
| 8/12 | 33.7° | × 1.202 |
| 9/12 | 36.9° | × 1.250 |
| 10/12 | 39.8° | × 1.302 |
| 12/12 | 45.0° | × 1.414 |
How pitch changes the price
- Area. A 12/12 roof has 41% more surface than its footprint — that is 41% more material and labor.
- Labor pace. Above roughly 8/12, crews need roof jacks, harnesses, and more staging time; above 10/12 many roofers add an explicit steep charge.
- Complexity. Our satellite estimator reads each section's pitch from the imagery data and folds steep sections into its complexity factor automatically.
Find your pitch
From the attic, hold a level against a rafter and measure the vertical rise over 12 horizontal inches. Or skip it: the satellite estimator reports your dominant pitch from imagery, free.
Run your own numbers: the satellite estimator and the roof cost calculator are both free, and both use the published dataset on our methodology page.