Calculate any
roof pitch instantly.
Convert between roof pitch (x:12), slope angle in degrees, rise, and run. Get accurate roofing measurements for rafters, shingles, and construction projects.
Measure any roof in 3 steps.
Pick Your Input Mode
Choose pitch, degrees, or rise/run. Each mode lets you enter the values you already know.
Enter Your Measurements
Type in the rise and run, angle, or pitch ratio you measured on the roof. All conversions update instantly.
Get Every Value
See the pitch (x:12), angle in degrees, slope %, and rafter length in one view — ready for cutting and materials.
Roof Pitch Conversion Chart
Common roof pitches with their equivalent slope angle, slope percentage, and typical use cases.
| Pitch (x:12) | Angle (°) | Slope (%) | Typical Use |
|---|---|---|---|
| 1:12 | 4.76° | 8.3% | Flat / low-slope commercial |
| 2:12 | 9.46° | 16.7% | Minimum for shingles (some codes) |
| 3:12 | 14.04° | 25.0% | Low-slope porch or shed roofs |
| 4:12 | 18.43° | 33.3% | Common residential; steep enough for shingles |
| 5:12 | 22.62° | 41.7% | Standard residential roof |
| 6:12 | 26.57° | 50.0% | Very common residential pitch |
| 7:12 | 30.26° | 58.3% | Steeper residential / snow shedding |
| 8:12 | 33.69° | 66.7% | Steep roof; good drainage |
| 9:12 | 36.87° | 75.0% | Steep; often requires harnesses |
| 10:12 | 39.81° | 83.3% | Very steep; snow and rain shedding |
| 12:12 | 45.00° | 100.0% | 45° roof; steep, dramatic look |
Frequently Asked Questions.
Roof pitch describes the steepness of a roof. It's usually written as a ratio of rise over run, such as 4:12, meaning the roof rises 4 inches for every 12 inches of horizontal run. It can also be expressed as an angle in degrees.
To convert roof pitch (x:12) to degrees, use the formula: angle = arctan(x / 12). For example, a 6:12 pitch gives arctan(0.5) ≈ 26.57°. The calculator does this automatically.
Roof pitch depends on climate and roofing material. A 4:12 to 6:12 pitch is common for residential homes, while steeper pitches (8:12 and above) shed water and snow better. Flat roofs (under 2:12) require special waterproofing.
Rafter length can be calculated using the Pythagorean theorem: rafter = √(rise² + run²). For a 6:12 pitch with a 12-foot run: rise = 6 ft, rafter = √(36 + 144) = √180 ≈ 13.42 ft. Our calculator returns this automatically.
Slope percentage is rise divided by run, multiplied by 100. A 6:12 pitch has a rise/run of 0.5, so the slope is 50%. This is often used in civil engineering and drainage calculations.
Yes, the roof pitch calculator is 100% free with no signup required. Use it as often as you like for your construction, roofing, or DIY projects.