Roof Pitch to Degrees
Convert roof pitch ratios to degrees, compare common roof angles and slope percentages, and use the calculator to convert your own rise and run measurements.
To convert roof pitch to degrees, divide the rise by the run and calculate the arctangent. For example, a 6/12 roof pitch equals 26.57°, while an 8/12 pitch equals 33.69°.
How to Convert Roof Pitch to Degrees
Roof pitch describes the relationship between the vertical rise of a roof and its horizontal run. In the commonly used X:12 format, the second number represents 12 units of horizontal run.
A 4/12 pitch therefore rises 4 units over a horizontal run of 12 units. To find the roof angle, divide 4 by 12 and calculate the inverse tangent of the result.
This same formula works with any rise and run as long as both measurements use the same unit.
Example for a 6/12 pitch:
So a 6/12 roof pitch has an angle of approximately 26.57 degrees.
Roof Pitch to Degrees Calculator
Enter rise and run, an existing pitch ratio or roof angle to calculate pitch, degrees, slope percentage, rafter length and pitch factor.
Enter your roof measurements and calculate instantly.
Roof Pitch to Degrees Chart
Use this chart to convert common roof pitch ratios from 1/12 through 12/12 into degrees and slope percentages.
| Roof Pitch | Degrees | Slope | Pitch Factor |
|---|---|---|---|
| 1/12 | 4.76° | 8.33% | 1.003 |
| 2/12 | 9.46° | 16.67% | 1.014 |
| 3/12 | 14.04° | 25.00% | 1.031 |
| 4/12 | 18.43° | 33.33% | 1.054 |
| 5/12 | 22.62° | 41.67% | 1.083 |
| 6/12 | 26.57° | 50.00% | 1.118 |
| 7/12 | 30.26° | 58.33% | 1.158 |
| 8/12 | 33.69° | 66.67% | 1.202 |
| 9/12 | 36.87° | 75.00% | 1.250 |
| 10/12 | 39.81° | 83.33% | 1.302 |
| 11/12 | 42.51° | 91.67% | 1.357 |
| 12/12 | 45.00° | 100.00% | 1.414 |
Roof Pitch and Degree Conversion Formulas
You can convert in either direction using basic trigonometry.
Convert Roof Pitch to Degrees
Divide rise by run, then calculate the inverse tangent.
For a 4/12 pitch: arctan(4 ÷ 12) ≈ 18.43°.
Convert Degrees to Roof Pitch
Take the tangent of the roof angle and multiply the result by 12.
For a 45° roof: tan(45°) × 12 = 12, giving a 12/12 pitch.
Common Roof Pitch Degree Conversions
Open the dedicated guide for more detailed calculations and measurements.
Roof Pitch to Degrees FAQs
Quick answers to common roof pitch and angle conversion questions.
What degree angle is a 4/12 roof pitch?
A 4/12 roof pitch is approximately 18.43 degrees.
What degree angle is a 6/12 roof pitch?
A 6/12 roof pitch is approximately 26.57 degrees.
What degree angle is an 8/12 roof pitch?
An 8/12 roof pitch is approximately 33.69 degrees.
What roof pitch is 45 degrees?
A 45-degree roof corresponds to a 12/12 roof pitch, because rise and horizontal run are equal.
How do I convert roof pitch to degrees?
Divide the roof rise by the horizontal run and calculate the inverse tangent of that result.
How do I convert degrees back to roof pitch?
Calculate the tangent of the roof angle and multiply by 12 to find the corresponding rise in a standard X/12 pitch format.
Is roof pitch the same as roof angle?
They describe the same incline in different ways. Roof pitch is normally expressed as rise over run, while roof angle is measured in degrees.
Calculate Your Roof Pitch
Enter rise and run or a known roof angle to calculate pitch ratio, degrees, slope, rafter length and pitch factor.
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