What a 6/12 pitch means
Pitch is written as rise over a 12 inch run. On a 6/12 roof, if you hold a level 12 inches out from the roof, the roof surface is 6 inches below the far end of the level.
Pitch factor = √(1 + (6/12)²) = 1.1180
The pitch factor means a 6/12 roof has 11.8% more surface than the floor area it covers. A 1,500 sq ft plan becomes 1,677 sq ft of roof.
6/12 rafter lengths
| Rafter run | Rise at ridge | Rafter length | Building width |
|---|---|---|---|
| 10 ft | 5 ft 0 in | 11 ft 2 in | 20 ft |
| 12 ft | 6 ft 0 in | 13 ft 5 in | 24 ft |
| 14 ft | 7 ft 0 in | 15 ft 8 in | 28 ft |
| 16 ft | 8 ft 0 in | 17 ft 11 in | 32 ft |
| 18 ft | 9 ft 0 in | 20 ft 1 in | 36 ft |
| 20 ft | 10 ft 0 in | 22 ft 4 in | 40 ft |
Lengths run from the ridge centerline to the outside of the wall, with no overhang. Add overhang with the rafter calculator.
Want a pro to confirm these numbers?
Numbers look right? A licensed roofer can measure on site and give you an exact price.
Where it is used
The most common US home pitch, used on gable and hip roofs of all styles. Popular nationwide.
Roofing materials for this pitch
Every steep-slope material works: shingles, standing seam, tile, slate and shakes.
Working on the roof
- Walkability: Walkable for roofers in dry conditions.
- Attic: Usable attic storage and room for insulation.
- Cost: Standard labor pricing. Usually the last pitch before steep-roof charges.
Compare nearby pitches
| Pitch | Degrees | Percent | Factor | Extra area |
|---|---|---|---|---|
| 4/12 | 18.43° | 33.3% | 1.054 | 5.4% |
| 5/12 | 22.62° | 41.7% | 1.083 | 8.3% |
| 6/12 | 26.57° | 50.0% | 1.118 | 11.8% |
See every pitch in the roof pitch chart.
Sources and further reading
- 2021 International Residential Code, Chapter 9: Roof Assemblies
- 2021 International Residential Code, Chapter 8: Roof-Ceiling Construction
- National Roofing Contractors Association (NRCA)
Frequently asked questions
How many degrees is a 6/12 roof pitch?
A 6/12 pitch is 26.57 degrees.
What is the pitch factor for 6/12?
1.118. Multiply the flat footprint by 1.118 to get the sloped roof area.
Can you use shingles on a 6/12 roof?
Yes, with standard installation.
Is a 6/12 roof walkable?
Walkable for roofers in dry conditions.
What percent slope is 6/12?
50.0%.