Roof Pitch Guide â Complete Reference
Roof pitch determines what materials you can use, how your roof sheds water, and how much material you need. This guide covers every common pitch from flat to steep with angles, multipliers, and compatible materials.
Complete Roof Pitch Chart
| Pitch | Degrees | % | Multiplier | Category | Compatible Materials |
|---|---|---|---|---|---|
| Flat (0/12) | 0° | 0% | 1.000 | Flat | TPO, EPDM, Built-up, Modified Bitumen |
| 1/12 | 4.8° | 8.3% | 1.003 | Low | TPO, EPDM, Modified Bitumen |
| 2/12 | 9.5° | 16.7% | 1.014 | Low | TPO, EPDM, Metal (with sealant) |
| 3/12 | 14.0° | 25.0% | 1.031 | Low | Metal, Rolled roofing, some shingles with special underlayment |
| 4/12 | 18.4° | 33.3% | 1.054 | Moderate | Asphalt shingles (minimum), Metal |
| 5/12 | 22.6° | 41.7% | 1.083 | Moderate | Asphalt shingles, Metal, Wood shake |
| 6/12 | 26.6° | 50.0% | 1.118 | Moderate | All standard materials |
| 7/12 | 30.3° | 58.3% | 1.158 | Steep | All standard materials |
| 8/12 | 33.7° | 66.7% | 1.202 | Steep | All standard materials, Tile |
| 9/12 | 36.9° | 75.0% | 1.250 | Steep | All standard materials, Slate, Tile |
| 10/12 | 39.8° | 83.3% | 1.302 | Very Steep | Shingles (with extra fasteners), Metal, Slate |
| 11/12 | 42.5° | 91.7% | 1.357 | Very Steep | Metal, Slate (special installation) |
| 12/12 | 45.0° | 100% | 1.414 | Very Steep | Metal, Slate (special installation) |
How to Measure Roof Pitch
From the Attic
- Hold a level horizontally against a rafter
- Mark 12 inches along the level from the rafter
- Measure vertically from the 12-inch mark to the rafter
- This vertical measurement is the rise per 12 inches of run
From Outside
- Measure the total height of the roof peak above the eave
- Measure the horizontal distance from the eave to directly below the peak
- Divide the height by the horizontal distance, then multiply by 12
Pitch Categories Explained
Flat (0/12 - 1/12)
Requires membrane roofing (TPO, EPDM, built-up). Water drains slowly, so waterproofing is critical. Common on commercial buildings and modern residential designs.
Low Slope (2/12 - 3/12)
Metal roofing works with proper sealant at seams. Most shingles are not rated for this slope. Special underlayment required.
Moderate (4/12 - 6/12)
The sweet spot for most residential roofs. All common materials work well. Walkable with standard precautions. Good water shedding.
Steep (7/12 - 9/12)
Excellent water shedding. Creates more attic space. All materials work but installation is more difficult and costly. Roof jacks may be needed.
Very Steep (10/12+)
Dramatic appearance. Requires safety equipment for installation. Extra fasteners needed for shingles. Metal and slate work best at these angles.