🔨 Wondering what your roof pitch is? Over 75,000 US homeowners and contractors use our free roof pitch calculator 2026 to determine roof slope, angles, and rafter lengths. Get accurate measurements for your next roofing project in seconds. ⭐ 4.9/5 (12,500+ reviews)
❓ Frequently Asked Questions About Roof Pitch
What is my roof pitch and how do I find it?
Your roof pitch is the slope of your roof, expressed as a ratio of rise (vertical) over run (horizontal). To find it: Place a level against your roof, measure 12 inches horizontally from the bottom, then measure vertically from the level down to the roof surface. That number is your rise (e.g., 6 inches rise = 6:12 pitch). You can also use our calculator above by entering your rise and run measurements.
What is the most common roof pitch for US homes?
The most common roof pitch for American homes is between 4:12 and 9:12, with 6:12 being the most popular. This pitch range works well with standard asphalt shingles, provides good water drainage, and is safe enough for most contractors to walk on. It's also aesthetically pleasing for colonial, ranch, and contemporary home styles.
How do I calculate my roof pitch from the ground?
You can estimate roof pitch from the ground using: 1) Smartphone apps with pitch measurement features, 2) Pitch finder tools available at hardware stores, 3) Measuring the gable end with a tape measure and level (measure the triangle shape of the exterior wall). For exact measurements, attic access or roof access with proper safety equipment is recommended.
What roof pitch do I need for my roofing material?
Different materials require minimum pitches: Asphalt shingles: minimum 2:12 (requires double underlayment below 4:12). Metal roofing: minimum 1:12 for standing seam, 3:12 for corrugated. Clay/concrete tiles: minimum 4:12. Wood shakes: minimum 4:12. Slate: minimum 4:12. Low-slope materials: designed for 1/4:12 to 3:12. Use our calculator to check your pitch and see material compatibility.
How does roof pitch affect roofing costs?
Steeper roofs (9:12+) cost 20-40% more than conventional pitches (4:12-9:12) because: 1) More material is needed for the same floor area, 2) Labor costs increase due to safety requirements, 3) Installation takes longer, 4) Walking and material handling is more difficult. Very steep roofs (12:12+) may cost 50-100% more due to specialized equipment and safety systems required.
Can I walk on my roof to check the pitch?
Safety first! Only walk on roofs with pitch under 7:12 and only when dry. For steeper roofs, always use: 1) Roof safety harness with anchor points, 2) Roof ladders or ladder hooks, 3) Non-slip footwear. Never walk on wet, icy, or steep roofs. Consider attic measurements or professional help instead.
What does 6:12 roof pitch mean?
A 6:12 roof pitch means the roof rises 6 inches vertically for every 12 inches of horizontal run. This equals a 26.6-degree angle, 50% slope, and is classified as a conventional slope. It's the most common residential roof pitch in the US, working well with standard shingles and providing good water drainage.
How do I calculate rafter length for my roof pitch?
Rafter length = √(rise² + run²). For example, with a 6:12 pitch and 20-foot span, run = 10 feet (half span), rise = 5 feet (10 × 0.5). Rafter length = √(10² + 5²) = 11.18 feet. Our calculator above automatically computes rafter length based on your roof width and pitch. Remember to add overhang for eaves.
Different roofing materials require minimum pitches. Use our calculator to check if your roof pitch works with your preferred material: