Use degrees for angle readings
Match the degrees column to a plan, digital level, or angle finder. To solve a real sloped member from rise and run, use the rafter calculator.
Roof Pitch Chart
Convert common X/12 roof pitches to degrees, slope percent, pitch multiplier, and rafter length per foot of run.
Need the pitch first? Measure your pitch with the roof pitch calculator →
X/12 roof pitch conversion chart
Values use full-precision roof geometry before display rounding.
Scroll sideways for more columns. Pitch stays visible.
| Pitch | Degrees | Slope | Multiplier | Rafter / 12" run | Class |
|---|---|---|---|---|---|
| 1/12 | 4.8° | 8.3% | 1.003 | 1.003 ft | Flat |
| 2/12 | 9.5° | 16.7% | 1.014 | 1.014 ft | Low slope |
| 3/12 | 14.0° | 25.0% | 1.031 | 1.031 ft | Low slope |
| 4/12 | 18.4° | 33.3% | 1.054 | 1.054 ft | Conventional |
| 5/12 | 22.6° | 41.7% | 1.083 | 1.083 ft | Conventional |
| 6/12 | 26.6° | 50.0% | 1.118 | 1.118 ft | Conventional |
| 7/12 | 30.3° | 58.3% | 1.158 | 1.158 ft | Conventional |
| 8/12 | 33.7° | 66.7% | 1.202 | 1.202 ft | Conventional |
| 9/12 | 36.9° | 75.0% | 1.250 | 1.250 ft | Conventional |
| 10/12 | 39.8° | 83.3% | 1.302 | 1.302 ft | Steep |
| 11/12 | 42.5° | 91.7% | 1.357 | 1.357 ft | Steep |
| 12/12 | 45.0° | 100.0% | 1.414 | 1.414 ft | Steep |
Convert any pitch or angle
Enter a rise per 12 or an angle. Results update as you type.
/ 12
- Pitch
- 6.0/12
- Degrees
- 26.6°
- Slope
- 50.0%
- Multiplier
- 1.118
- Rafter / 12"
- 1.118 ft
How to read this chart
Use the multiplier for area
Multiply horizontal projected area by the pitch multiplier to estimate sloped surface area. Continue with the roofing calculator for waste, roofing squares, and bundles. For the complete ground-measurement sequence, see how to calculate roof square footage.
Use classification as a reference
Flat is under 2/12, low slope is 2/12 to under 4/12, conventional is 4/12 through 9/12, and steep is above 9/12. Material and code limits still control. See the methodology for formulas and rounding.
Common roof pitch quick answers
Three conventional pitches, calculated with the same roof-math engine.
4/12 roof pitch
18.4° · 33.3% slope · 1.054 pitch multiplier.
6/12 roof pitch
26.6° · 50.0% slope · 1.118 pitch multiplier.
8/12 roof pitch
33.7° · 66.7% slope · 1.202 pitch multiplier.
Roof pitch chart FAQ
Quick answers for reading and applying roof pitch conversions.
How do I convert an X/12 roof pitch to degrees?
Divide the rise by 12, take the arctangent, and convert radians to degrees. The chart performs that geometry for each common pitch from 1/12 through 12/12.
What is the pitch multiplier used for?
The pitch multiplier converts horizontal projected area to sloped roof area. Multiply the footprint of a uniform roof section by the factor, then add waste separately when estimating materials.
What roof pitch is 45 degrees?
A 45-degree roof has a 12/12 pitch, a 100% slope, and a pitch multiplier of about 1.414.
What is the difference between low, conventional, and steep pitch?
This chart labels 2/12 to under 4/12 as low slope, 4/12 through 9/12 as conventional, and above 9/12 as steep. Under 2/12 is labeled flat. Product and code requirements still govern real installations.
Does the rafter column include cuts or overhang?
No. It is the geometric sloped length for one foot of horizontal run. It does not include overhang, ridge deductions, birdsmouth, plumb cuts, or structural design allowances.