Typical pitch by building type
| Building | Usual pitch | Notes |
|---|---|---|
| Ranch house | 4/12 to 6/12 | Low, wide profile |
| Two-story house | 6/12 to 9/12 | Steeper to balance the height |
| Cape Cod, Tudor, Victorian | 8/12 to 12/12 | Steep gables, often usable attic |
| Detached garage | 4/12 to 6/12 | Usually matches the house |
| Porch or lean-to | 2/12 to 4/12 | Low pitch; check roofing minimums |
| Metal building or barn | 1/2:12 to 4/12 | Panels drain at low slopes |
| A-frame | 12/12 and up | 45 degrees or steeper |
Style and region decide, not a rule. Cold, snowy regions lean steeper, and low-slope and flat roofs are common in dry climates.
What each pitch costs in area
For the same house, a steeper roof has more surface to cover. The table uses a 2,000 sq ft footprint with overhang and compares with 4/12:
| Pitch | Angle | Roof area | Squares | Extra vs 4/12 |
|---|---|---|---|---|
| 3/12 | 14.0° | 2,062 sq ft | 20.6 | -47 sq ft |
| 4/12 | 18.4° | 2,108 sq ft | 21.1 | +0 sq ft |
| 5/12 | 22.6° | 2,167 sq ft | 21.7 | +58 sq ft |
| 6/12 | 26.6° | 2,236 sq ft | 22.4 | +128 sq ft |
| 7/12 | 30.3° | 2,315 sq ft | 23.2 | +207 sq ft |
| 8/12 | 33.7° | 2,404 sq ft | 24.0 | +296 sq ft |
| 9/12 | 36.9° | 2,500 sq ft | 25.0 | +392 sq ft |
| 10/12 | 39.8° | 2,603 sq ft | 26.0 | +495 sq ft |
| 12/12 | 45.0° | 2,828 sq ft | 28.3 | +720 sq ft |
The step from 4/12 to 8/12 adds 14% to the roof area. That is why a steeper roof costs more even before extra labor is counted.
How to pick a pitch
- Roofing. Shingles need 4/12 for a standard job. See the shingle minimum pitch page.
- Safety and cost. Roofs steeper than 6/12 need more equipment to work on.
- Appearance and space. A steeper roof gives more attic volume and a more traditional look.
Find your own pitch with the roof pitch calculator, or read what roof pitch means. Each pitch has a page with rafter lengths and materials, from 1/12 to 12/12.
Frequently asked questions
What is the most common roof pitch?
Between 4/12 and 9/12 for most houses, with 6/12 one of the most common.
What is a normal roof pitch for a house?
4/12 to 9/12. Ranch houses are on the lower end and two-story houses on the higher end.
What is a standard roof pitch for a garage?
Usually 4/12 to 6/12, often matched to the house.
Sources
- LSU AgCenter: Code-Compliant Roofing Installations (PDF)
- Cornell LII: 29 CFR 1926.500, definitions of low-slope and steep roofs