What is a 6/12 roof pitch in degrees?
A 6/12 pitch is 26.6 degrees, which is a 50.0% grade. The roof area is 1.118 times the footprint.
Roof Pitch Calculator: Rise and Run to Pitch, Degrees and Slope
Enter the rise and run you measured, an angle in degrees or a percent grade. The calculator returns the pitch as rise in 12, the angle, the percent grade and the multiplier that turns a flat footprint into true sloped roof area.
Pitch from measurements
Pitch (rise in 12)
6.0/12
Angle
26.6°
Percent grade
50.0%
Roof area multiplier
×1.118
Roof surface for this footprint: 1,118 sq ft (11.18 roofing squares)
How roof pitch, angle and slope fit together
Roof pitch states how many inches the roof rises for every 12 inches of horizontal run. A 6/12 roof rises 6 in over 12 in, which is an angle of 26.6 degrees and a slope of 50.0%. Roof slope, pitch and grade all describe the same steepness; only the unit differs: x/12 in the United States, degrees in plans from abroad, percent for drainage.
To measure it, hold a level horizontally against a rafter or the roof surface, mark 12 in along the level and measure straight up to the rafter at that mark. That vertical distance is the rise per 12. You can also enter any rise and run you measured in the same unit, for example 4.0 ft of rise over 10 ft of run, which gives 4.8/12.
The area multiplier is √(1 + (rise ÷ 12)²). A roof is always larger than the footprint of the house under it: at 6/12 the multiplier is 1.118, so 1,000 sq ft of footprint becomes 1,118 sq ft of roof, or 11.2 roofing squares. At 12/12 it is 1.414. Add the eave overhang and a waste allowance in the roofing calculator to get shingle bundles and cost.
Roof pitch chart: angle, grade and area multiplier
| Pitch | Angle | Percent grade | Area multiplier | Roof area for 1,000 sq ft footprint |
|---|---|---|---|---|
| 1/12 | 4.8° | 8.3% | ×1.003 | 1,003 sq ft |
| 2/12 | 9.5° | 16.7% | ×1.014 | 1,014 sq ft |
| 3/12 | 14.0° | 25.0% | ×1.031 | 1,031 sq ft |
| 4/12 | 18.4° | 33.3% | ×1.054 | 1,054 sq ft |
| 5/12 | 22.6° | 41.7% | ×1.083 | 1,083 sq ft |
| 6/12 | 26.6° | 50.0% | ×1.118 | 1,118 sq ft |
| 7/12 | 30.3° | 58.3% | ×1.158 | 1,158 sq ft |
| 8/12 | 33.7° | 66.7% | ×1.202 | 1,202 sq ft |
| 9/12 | 36.9° | 75.0% | ×1.250 | 1,250 sq ft |
| 10/12 | 39.8° | 83.3% | ×1.302 | 1,302 sq ft |
| 11/12 | 42.5° | 91.7% | ×1.357 | 1,357 sq ft |
| 12/12 | 45.0° | 100.0% | ×1.414 | 1,414 sq ft |
Frequently Asked Questions & Field Guide
How do I convert degrees to roof pitch?
Multiply the tangent of the angle by 12. A 30 degree roof has a pitch of 6.9/12, close to 7/12. The calculator does this when you type the angle into the Angle field.
What is the formula for roof pitch?
Pitch = rise ÷ run × 12. A rise of 4 over a run of 10 is 4 ÷ 10 × 12 = 4.8, so the pitch is 4.8/12. Use the same unit for rise and run.
How do I find the roof area from the pitch?
Multiply the footprint (including overhang) by the multiplier √(1 + (rise ÷ 12)²). At 8/12 the multiplier is 1.202, so a 1,500 sq ft footprint gives 1,803 sq ft, or 18.0 roofing squares.
What is the minimum roof pitch for asphalt shingles?
The reference table on the roofing calculator lists 4/12 as the minimum for standard shingles and 2/12 as a low slope that needs double underlayment or a membrane. Always follow the shingle manufacturer and your local building code.