Quick Presets
Mathematical conversion only. Actual roof angles may vary due to construction tolerances.
Complete Pitch to Degrees Conversion Table
Reference table showing all standard roof pitches from 1/12 to 24/12 with their equivalent angle in degrees, slope percentage, and area multiplier.
| Pitch | Degrees | Slope % | Multiplier |
|---|---|---|---|
| 1/12 | 4.76° | 8.3% | 1.003 |
| 2/12 | 9.46° | 16.7% | 1.014 |
| 3/12 | 14.04° | 25.0% | 1.031 |
| 4/12 | 18.43° | 33.3% | 1.054 |
| 5/12 | 22.62° | 41.7% | 1.083 |
| 6/12 | 26.57° | 50.0% | 1.118 |
| 7/12 | 30.26° | 58.3% | 1.158 |
| 8/12 | 33.69° | 66.7% | 1.202 |
| 9/12 | 36.87° | 75.0% | 1.250 |
| 10/12 | 39.81° | 83.3% | 1.302 |
| 11/12 | 42.51° | 91.7% | 1.357 |
| 12/12 | 45.00° | 100.0% | 1.414 |
| 13/12 | 47.29° | 108.3% | 1.474 |
| 14/12 | 49.40° | 116.7% | 1.537 |
| 15/12 | 51.34° | 125.0% | 1.601 |
| 16/12 | 53.13° | 133.3% | 1.667 |
| 17/12 | 54.78° | 141.7% | 1.734 |
| 18/12 | 56.31° | 150.0% | 1.803 |
| 19/12 | 57.72° | 158.3% | 1.873 |
| 20/12 | 59.04° | 166.7% | 1.944 |
| 21/12 | 60.26° | 175.0% | 2.016 |
| 22/12 | 61.39° | 183.3% | 2.088 |
| 23/12 | 62.45° | 191.7% | 2.162 |
| 24/12 | 63.43° | 200.0% | 2.236 |
Values calculated using the formula: degrees = arctan(rise ÷ 12) × (180 ÷ π). Multiplier = √(1 + (rise/12)²).
4/12 Pitch in Degrees
A 4/12 roof pitch equals 18.43° — the boundary between low-slope and standard roofing.
Pitch
4/12
Angle
18.43°
Slope
33.3%
Multiplier
1.054
Code & Installation Requirements
This slope sits at the threshold defined by IRC Section R905.2.7: at 4:12 and above, standard asphalt shingle installation is permitted without the double-layer self-adhered underlayment required on lower slopes. GAF and CertainTeed both rate their architectural shingle lines for installation starting at 4:12. Standing seam and corrugated metal panels also perform well here since water velocity is already sufficient to clear panel seams.
Common Uses & Cost Impact
That code distinction makes 4/12 the go-to pitch for ranch-style homes, attached garages, and covered porches — builders get adequate drainage while keeping framing costs below steeper alternatives. The area multiplier of 1.054 means a 2,000 sq ft footprint needs roughly 2,108 sq ft of roofing material — only a 5.4% uplift over plan-view area.
Compatible Materials
5/12 Pitch in Degrees
A 5/12 roof pitch equals 22.62° — the most popular residential roof slope in the United States.
Pitch
5/12
Angle
22.62°
Slope
41.7%
Multiplier
1.083
Why Builders Prefer 5/12
According to the National Association of Home Builders (NAHB), pitches between 4/12 and 6/12 account for the majority of new single-family starts, with 5/12 being the single most specified slope in production-home plans. The reason is economics: a 5/12 truss costs only 5–8% more than a 4/12 truss of the same span, yet the steeper angle noticeably improves curb appeal and water-shedding speed.
Walkability, Materials & Coverage
Roofing crews can still walk a 5/12 surface without harness equipment under most jobsite safety plans, keeping labor rates at the "walkable" tier. Every mainstream material works here — asphalt shingles, wood shakes, clay tiles, standing seam metal, and corrugated panels all meet or exceed their manufacturer-stated minimum slope. With a multiplier of 1.083, a 30-square roof (3,000 sq ft footprint) needs about 32.5 squares of material.
Compatible Materials
6/12 Pitch in Degrees
A 6/12 roof pitch equals 26.57° — the upper boundary of standard slope, ideal for snow and rain regions.
Pitch
6/12
Angle
26.57°
Slope
50.0%
Multiplier
1.118
Drainage & Snow Performance
Where 5/12 optimizes for cost, 6/12 optimizes for weather performance. The additional 4 degrees of steepness increases gravitational water velocity by roughly 18%, which matters in FEMA-designated high-rainfall zones (annual precipitation > 60 in.) and areas with moderate snow loads (30–50 psf ground snow per ASCE 7).
Slate, Cost & Architectural Fit
Natural slate manufacturers — including Vermont Structural Slate and North Country Slate — specify 6:12 as their minimum installation slope; below that, water infiltration risk at overlaps increases to unacceptable levels. The trade-off is a 1.118 multiplier: on a 2,500 sq ft footprint, you need 2,795 sq ft of material, roughly $800–$1,200 more in asphalt shingles versus the same home at 4/12. Cape Cod and Colonial Revival plans almost universally feature 6/12 main roofs paired with steeper dormers.
Compatible Materials
How Pitch to Degrees Conversion Works
The mathematical relationship between roof pitch and degrees uses basic trigonometry.
Pitch to Degrees
degrees = arctan(rise ÷ run) × (180 ÷ π)
For a 6/12 pitch: arctan(6 ÷ 12) × 57.2958 = 26.57°
Degrees to Pitch
pitch = tan(degrees × π ÷ 180) × 12
For 30°: tan(30 × 0.01745) × 12 = 6.93 ≈ 7/12 pitch
Why 12?
The US construction industry standardizes roof pitch as rise per 12 inches of horizontal run. This convention dates back to framing squares used by carpenters, which are marked in 12-inch increments. The 12-based system makes field measurements simple: place a level horizontally, measure 12 inches out, then measure the vertical rise at that point.
Frequently Asked Questions
Common questions about converting between roof pitch and degrees.