Roof Pitch Calculator
Measure with your phone, quick-add standard pitches, or calculate roof area with waste
Manual Entry
Enter the angle in degrees if you prefer manual entry:
Standard Roof Pitches
Tap a pitch to add it as a measurement
Understanding Roof Pitch
Roof pitch is the slope of your roof, expressed as a ratio of rise to run.
What is Roof Pitch?
Pitch is expressed as "X:12" where X is how many inches the roof rises for every 12 inches of horizontal run. A 6:12 pitch rises 6 inches per foot.
Why Pitch Matters
- • Determines material requirements
- • Affects labor costs (steeper = harder)
- • Impacts drainage and durability
- • Required for accurate estimates
How to Use This Tool
- 1. Enable motion sensors
- 2. Place phone against roof surface
- 3. Hold steady for 5 seconds
- 4. Confirm and save measurement
Roof Pitch Reference Chart
Use this chart to understand different roof pitches, their angles, and common applications.
| Pitch | Angle | Category |
|---|---|---|
| 1:12 | 4.8° | Flat |
| 2:12 | 9.5° | Low Slope |
| 3:12 | 14.0° | Low Slope |
| 4:12 | 18.4° | Walkable |
| 5:12 | 22.6° | Walkable |
| 6:12 | 26.6° | Standard |
| 7:12 | 30.3° | Standard |
| 8:12 | 33.7° | Standard |
| 9:12 | 36.9° | Steep |
| 10:12 | 39.8° | Steep |
| 12:12 | 45.0° | Very Steep |
* Multiplier is used to convert flat area to actual roof area. Multiply your home's footprint by the multiplier to estimate roof surface area.
Frequently Asked Questions
Common questions about roof pitch and how to measure it.
What is the most common roof pitch?
The most common roof pitch in residential construction is 6:12, which means the roof rises 6 inches for every 12 inches of horizontal run. This pitch provides a good balance between aesthetic appeal, water drainage, and ease of installation. In the Pacific Northwest, pitches between 4:12 and 8:12 are most common due to the rainy climate.
How do I measure roof pitch with my phone?
Using our roof pitch calculator, simply enable your phone's motion sensors, then place your phone flat against the roof surface (parallel to the shingles). Hold it steady for 5 seconds, and the calculator will automatically detect the angle and convert it to the standard pitch ratio. You can also manually enter the angle if you prefer.
What is the minimum roof pitch for shingles?
The minimum recommended pitch for standard asphalt shingles is 4:12. For pitches between 2:12 and 4:12, special low-slope application methods with additional underlayment are required. Below 2:12, asphalt shingles are generally not recommended, and alternative roofing materials like rolled roofing, TPO, or EPDM should be used.
Why does roof pitch affect roofing costs?
Steeper roofs cost more for several reasons: they require more safety equipment and take longer to work on, more materials are needed to cover the larger surface area, and specialized installation techniques may be required. A 12:12 pitch roof has about 41% more surface area than a flat roof of the same footprint.
What pitch is considered a 'walkable' roof?
Roofs with a pitch of 6:12 or less are generally considered walkable without special equipment. At 7:12 to 9:12, the roof becomes more challenging and may require roof jacks or toe boards. Above 9:12, roofs are considered steep and typically require harnesses, scaffolding, or other safety equipment for workers.
How do I convert roof pitch to degrees?
To convert pitch to degrees, use the formula: degrees = arctan(rise/12) × (180/π). For example, a 6:12 pitch equals arctan(6/12) = 26.57 degrees. Our calculator does this conversion automatically. Common conversions: 4:12 = 18.4°, 6:12 = 26.6°, 8:12 = 33.7°, 12:12 = 45°.
What is a roof pitch multiplier?
The pitch multiplier (also called the roof slope factor) is used to calculate actual roof surface area from a home's footprint. It accounts for the extra material needed due to the slope. Formula: multiplier = √(1 + (rise/12)²). For a 6:12 pitch, the multiplier is 1.118, meaning a 2,000 sq ft footprint would have approximately 2,236 sq ft of roof surface.
Does roof pitch affect energy efficiency?
Yes, roof pitch can impact energy efficiency. Steeper roofs have more attic space for insulation and ventilation, which can improve energy efficiency. They also shed snow and debris more easily. However, steeper roofs have more surface area exposed to the sun, which can increase heat gain in summer. The optimal pitch depends on your climate and orientation.
Can I change my roof pitch?
Changing roof pitch is possible but involves significant structural modifications. It typically requires rebuilding the entire roof framing system, which is a major construction project. This is usually only done during major renovations or when adding a second story. Consult with a structural engineer and licensed contractor before considering such changes.
What roof pitch is best for solar panels?
The optimal roof pitch for solar panels depends on your latitude. In the Pacific Northwest (around 45° latitude), a pitch between 30° and 45° (approximately 7:12 to 12:12) is ideal for maximum annual solar energy production. However, modern solar panels are efficient across a wide range of angles, and even flat or low-slope roofs can effectively support solar installations with proper mounting systems.
Pro Tips for Measuring Roof Pitch
1Measure From Inside the Attic
The safest way to measure roof pitch is from inside your attic. Place a level against a rafter and measure 12 inches along it, then measure the vertical rise. This gives you the pitch without climbing on the roof.
2Check Multiple Sections
Many homes have multiple roof pitches, especially on complex rooflines. Measure each section separately for accurate material estimates. Our calculator lets you save up to 10 different measurements.
3Account for Waste Factor
Always add 10-20% extra material for waste when ordering roofing supplies. Complex roofs with many valleys, hips, and dormers may require up to 25% waste factor due to additional cutting and fitting.
4Lock Screen Rotation
When using your phone to measure roof pitch, lock your screen rotation to portrait mode for the most accurate readings. This prevents the display from flipping as you tilt your phone against the roof surface.
Need a Professional Roof Assessment?
Our experts can provide accurate measurements and a detailed inspection. Schedule a free inspection today.