Convert a roof pitch such as 6/12 to degrees and percent slope, and back
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.A pitch of x/12 means x inches of rise for every 12 inches of run, and its angle is the arctangent of x divided by 12. A 6/12 roof is 26.57 degrees and a 50% slope; 12/12 is 45 degrees. Enter a pitch, an angle or a measured rise and run to convert between all three.
| Pitch | Degrees | Percent slope | Area multiplier |
|---|---|---|---|
| 1/12 | 4.76° | 8.3% | 1.004 |
| 2/12 | 9.46° | 16.7% | 1.014 |
| 3/12 | 14.04° | 25% | 1.031 |
| 4/12 | 18.43° | 33.3% | 1.054 |
| 5/12 | 22.62° | 41.7% | 1.083 |
| 6/12 | 26.57° | 50% | 1.118 |
| 7/12 | 30.26° | 58.3% | 1.158 |
| 8/12 | 33.69° | 66.7% | 1.202 |
| 9/12 | 36.87° | 75% | 1.250 |
| 10/12 | 39.81° | 83.3% | 1.302 |
| 12/12 | 45.00° | 100% | 1.414 |
Pitch is already selected under "I know the"; type a pitch such as 6 for 6/12.
Read the angle in degrees and the percent slope under the Pitch result.
To go the other way, pick Angle and enter degrees, or "Rise and run" and enter the measured inches.
Open "Common pitches" for a table of pitches in degrees, percent and multiplier.
Roofers, framers and building codes describe a roof's steepness in three ways: pitch as a rise over 12 (6/12), an angle in degrees (26.57), and a slope as a percentage (50%). This calculator converts between all three and then uses the pitch for the numbers a roofing or framing job needs.
Enter what you have. Type a pitch, an angle, or a rise and run measured on the roof or with a level and tape. The rise and run can be in any unit as long as both use the same one. The pitch is 12 times the rise divided by the run.
Roof area and squares. The same factor, the pitch multiplier, turns the footprint of the roof (its plan area, overhangs included) into the sloped area. That holds for any roof whose planes share one pitch, hips and valleys included. Roofing is ordered in squares of 100 square feet; add a waste allowance for cutting, starter rows and ridge caps, commonly around 10 percent for a simple gable and more for a cut-up roof.
The rest of the article, and all 6 questions about Roof Pitch Calculator, are on the Roof Pitch Calculator page.
A 6/12 roof rises 6 inches for every 12 inches of horizontal run. The angle is the arctangent of 6 divided by 12, which is 26.57 degrees, and the slope is 50 percent. A 4/12 roof is 18.43 degrees, an 8/12 roof is 33.69 degrees and a 12/12 roof is exactly 45 degrees.
Multiply the roof's footprint by the pitch multiplier to get the roof area, divide by 100 to get squares, and add waste. A 1,500 square foot footprint at 6/12 is 1,677 square feet, or 16.8 squares; with 10 percent waste that is 18.5 squares, or 56 bundles at 3 bundles a square.
Hold a level horizontally against the roof or a rafter, mark 12 inches along the level, and measure straight up from that mark to the roof surface. That distance in inches is the pitch over 12. You can also measure any rise and run, enter both, and the calculator converts them.
The two words are often used interchangeably. Strictly, slope is the rise over the run, written as x/12 or as a percentage, while pitch has at times meant the rise over the full span. Most US roofers and codes now say pitch or slope for the same x/12 figure, which is what this calculator uses.
Formula only: no rates or limits are read from an official source.
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