Roof Pitch to Degrees: Conversion Chart & Guide

A 4/12 roof pitch equals 18.4 degrees, a 6/12 pitch equals 26.6 degrees, and a 12/12 pitch equals exactly 45 degrees. To convert any pitch to degrees, take the arctangent of the rise divided by 12 — or just use the complete chart below. This guide covers every standard pitch conversion, the formula behind it, and situations where degrees matter more than ratios.

Table of Contents

• How Pitch and Degrees Relate
• Complete Pitch to Degrees Conversion Chart
• The Conversion Formula
• Common Pitches and Their Angles
• When You Need Degrees Instead of Pitch
• How to Measure Roof Angle Directly
• Pitch Categories and What They Mean
• FAQ

How Pitch and Degrees Relate

Roof pitch and degrees describe the same thing — how steep your roof is — just in different units. Pitch uses a ratio: the number of inches the roof rises vertically for every 12 inches it runs horizontally. Degrees measure the angle between the roof surface and a perfectly flat horizontal plane.

A 0/12 pitch is 0 degrees (dead flat). A 12/12 pitch is 45 degrees (equal rise and run). Anything steeper than 12/12 goes above 45 degrees, though that’s uncommon in residential construction.

The relationship isn’t linear. Going from 4/12 to 8/12 doubles the rise, but the angle only goes from 18.4° to 33.7° — not quite double. This is because the tangent function (which governs this relationship) curves as the angle increases.

Complete Pitch to Degrees Conversion Chart

Here’s every standard residential pitch from 1/12 through 12/12, plus some fractional pitches you might encounter:

Pitch	Degrees	Radians	Common Name
0.5/12	2.4°	0.042	Nearly flat
1/12	4.8°	0.083	Low slope
1.5/12	7.1°	0.124	Low slope
2/12	9.5°	0.165	Low slope
2.5/12	11.8°	0.206	Low slope
3/12	14.0°	0.245	Moderate
3.5/12	16.3°	0.284	Moderate
4/12	18.4°	0.322	Moderate
4.5/12	20.6°	0.359	Moderate
5/12	22.6°	0.395	Moderate
5.5/12	24.6°	0.430	Moderate
6/12	26.6°	0.464	Standard
6.5/12	28.4°	0.497	Standard
7/12	30.3°	0.528	Standard
7.5/12	32.0°	0.559	Standard
8/12	33.7°	0.588	Steep
8.5/12	35.3°	0.616	Steep
9/12	36.9°	0.644	Steep
9.5/12	38.4°	0.670	Steep
10/12	39.8°	0.695	Very steep
10.5/12	41.2°	0.719	Very steep
11/12	42.5°	0.742	Very steep
11.5/12	43.8°	0.764	Very steep
12/12	45.0°	0.785	Maximum standard

The Conversion Formula

If you want to convert any pitch to degrees yourself:

Degrees = arctan(rise ÷ 12) × (180 ÷ π)

Or more simply: take the inverse tangent (arctan or tan⁻¹) of the rise divided by 12.

Examples:

• 4/12: arctan(4/12) = arctan(0.333) = 18.43°
• 6/12: arctan(6/12) = arctan(0.5) = 26.57°
• 9/12: arctan(9/12) = arctan(0.75) = 36.87°

On a scientific calculator, make sure you’re in degree mode (not radians) before using the arctan function.

To go the other direction — degrees to pitch:

Rise = 12 × tan(degrees)

For 30 degrees: 12 × tan(30°) = 12 × 0.577 = 6.93, so a 30° roof is approximately a 7/12 pitch. For a more detailed guide on measuring and calculating pitch, see how to calculate roof pitch.

Common Pitches and Their Angles

Here are the pitches you’ll encounter most often in residential roofing, with context on where they’re typically found:

4/12 Pitch = 18.4 Degrees

The minimum pitch recommended for standard asphalt shingles. Common on ranch homes built in the 1960s–1980s, covered patios, and low-profile modern homes. Workers can walk this comfortably without harnesses. Material costs are near minimum since the area is only 5.4% more than flat.

5/12 Pitch = 22.6 Degrees

A popular choice for single-story homes and additions. Provides decent water runoff without excessive material use. Still walkable for most roofing crews without special equipment.

6/12 Pitch = 26.6 Degrees

The most common residential roof pitch in America. Offers good aesthetics, efficient water shedding, and reasonable material costs (11.8% more area than flat). This is the “default” pitch many builders use. Crews can work it comfortably, though some prefer roof jacks.

8/12 Pitch = 33.7 Degrees

Common on Colonial, Cape Cod, and traditional-style homes. Creates a more dramatic roofline and provides attic space. Requires toe boards or roof jacks for safe working. Material needs are 20.2% higher than flat, and labor carries a 15–25% surcharge.

10/12 Pitch = 39.8 Degrees

Found on Victorian, Tudor, and A-frame style homes. Creates significant attic space and dramatic curb appeal. Requires full harness and rope systems for workers. Material costs increase 30% over flat, with steep-pitch labor premiums of 25–40%.

12/12 Pitch = 45 Degrees

A 45-degree angle where rise equals run. Used on steep architectural features, church steeples, and A-frame cabins. Requires specialized steep-pitch crews. Material needs are 41.4% higher than flat, with the highest labor surcharges (30–50% or more).

When You Need Degrees Instead of Pitch

Most roofing work uses the pitch ratio — it’s how shingle manufacturers specify minimum slope, how lumber is cut, and how material is ordered. But there are specific situations where degrees are more useful:

Cutting Rafters and Joists

When setting a miter saw or circular saw for rafter bird’s mouth cuts or plumb cuts, you need the complement of the pitch angle. For a 6/12 pitch (26.6°), you’d set your saw to 63.4° (90° minus 26.6°) for a plumb cut.

Building Codes and Regulations

Some local building codes specify maximum roof angles in degrees rather than pitch, particularly for snow load requirements and fire setback calculations.

Comparing Different Slope Units

If you’re looking at European construction specs (which use degrees) or dealing with civil engineering slope requirements (which use percentages), converting pitch to degrees puts everything in comparable terms.

Solar Panel Installation

Solar panel efficiency depends on the angle of incidence relative to the sun. Installers need the roof angle in degrees to calculate optimal tilt and estimate energy output for your latitude.

Communicating With Non-Roofers

Architects, engineers, and homeowners often understand degrees more intuitively than pitch ratios. Saying “it’s a 34-degree roof” communicates steepness immediately, while “8/12” requires industry knowledge.

How to Measure Roof Angle Directly

If you want to measure the angle in degrees without converting from pitch:

Method 1: Digital Level App

Most smartphones have a level/inclinometer app. Place the phone flat against a rafter in the attic (parallel to the roof surface), and the app reads the angle directly. This is the fastest method.

Method 2: Speed Square

A speed square has degree markings along its hypotenuse edge. Hold the pivot point against the bottom edge of a rafter with the square hanging freely, and read where the plumb edge points on the degree scale.

Method 3: Protractor and Level

Place a standard level against the roof surface (or a rafter). Hold a protractor at the point where the level meets the roof surface, with the flat edge along the level. The roof surface angle reads off the protractor directly.

Method 4: Calculate From Rise and Run

Measure 12 inches horizontally along a rafter (use a level to keep it horizontal), then measure the vertical distance. Divide vertical by 12 and take the arctangent. Or just look it up in the chart above.

Pitch Categories and What They Mean

The roofing industry groups pitches into categories that affect material choices, labor costs, and safety requirements:

Flat to Low Slope (0–3/12 or 0°–14°)

Requires membrane roofing (TPO, EPDM, modified bitumen) or special low-slope shingles. Standard shingles are not rated for pitches below 2/12. Water drains slowly and ice dams are a concern in cold climates.

Moderate Slope (4/12–6/12 or 18°–27°)

The comfortable working range. Standard asphalt shingles perform well. Workers can walk without special equipment on most of this range. Material costs are moderate.

Steep Slope (7/12–9/12 or 30°–37°)

Requires roof jacks, toe boards, or personal fall protection. Labor costs increase 10–25%. All standard roofing materials work at these pitches. Water sheds quickly and ice dams are rare.

Very Steep Slope (10/12+ or 40°+)

Requires full harness, rope, and anchor systems. Labor premiums of 25–50%. Material waste increases because workers can’t easily handle bundles on the slope. Dramatic architectural appearance.

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FAQ

What degree is a 4/12 pitch?

A 4/12 roof pitch equals 18.43 degrees. This is considered a moderate slope and is the minimum pitch recommended by most asphalt shingle manufacturers for standard installation without special low-slope techniques.

What angle is a 6/12 pitch?

A 6/12 pitch equals 26.57 degrees. This is the most common residential roof pitch in the United States, offering a good balance between aesthetics, water shedding, and material efficiency.

Is a 12/12 pitch really 45 degrees?

Yes. A 12/12 pitch means the roof rises 12 inches for every 12 inches of horizontal run — equal rise and run. The arctangent of 12/12 (which equals 1) is exactly 45 degrees. This is the steepest “standard” pitch in residential construction.

How do I convert degrees back to pitch?

Multiply 12 by the tangent of your angle. For example, for a 30° roof: 12 × tan(30°) = 12 × 0.577 = 6.93 — approximately a 7/12 pitch. Our roof pitch calculator can do this conversion instantly.

What’s the minimum roof pitch for shingles?

Most asphalt shingle manufacturers require a minimum 4/12 pitch (18.4°) for standard installation. Some allow 2/12 (9.5°) with special underlayment and reduced warranty coverage. Below 2/12, you’ll need a flat roofing membrane system like TPO or EPDM. For more details on flat roof costs and materials, see our dedicated guide.

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Sources: Pitch multipliers derived from trigonometric calculations per ARMA (Asphalt Roofing Manufacturers Association) technical bulletins. Measurement methods follow NRCA (National Roofing Contractors Association) best practices.