21/12 roof pitch
60.26° angle
A 21/12 roof rises 21 in for every 12 in of run: a 175% slope with a 2.016 area multiplier.
| Pitch | 21 in 12 (21:12) |
|---|---|
| Angle | 60.26° |
| Slope | 175% |
| Roof area multiplier | 2.0156 |
| Rafter length per foot of run | 24.19 in |
| Type | A very steep roof |
Roofing for a 21/12 pitch
Suitable for asphalt shingles, metal, tile and most other roofing with standard underlayment. Not walkable: roofers work from roof jacks and fall protection, which adds labor cost.
Rafter length at 21/12
| Run (half the span) | Rise | Rafter length (before overhang) |
|---|---|---|
| 10 ft | 17.5 ft | 20.16 ft |
| 12 ft | 21 ft | 24.19 ft |
| 14 ft | 24.5 ft | 28.22 ft |
| 16 ft | 28 ft | 32.25 ft |
Change the numbers
Other roof pitches
Questions
- What angle is a 21/12 roof pitch?
- 60.26 degrees.
- What is a 21/12 roof pitch as a percentage?
- 175%: the roof rises 21 inches for every 12 inches of run.
- What is the roof multiplier for a 21/12 pitch?
- 2.016. Multiply the roof’s flat footprint by 2.016 to get its actual surface area.
- Is a 21/12 roof walkable?
- Not walkable: roofers work from roof jacks and fall protection, which adds labor cost.