How do you determine your roof pitch without climbing on the roof?
Short answer. You can determine roof pitch without climbing on the roof by measuring a rafter in the attic, photographing a gable end and measuring the angle, using a phone app from the ground, checking house plans, or reading an aerial measurement report. Each gives a usable number; the attic rafter method is usually the most accurate.
Five no climb methods
- Attic rafter. Hold a level against the underside of a rafter, measure 12 inches along the level, then measure straight up to the rafter. That vertical distance is the pitch. A phone level app laid on the rafter gives the angle in degrees.
- Gable photo. Stand square to a gable end, take a straight on photo, and measure the roof angle with a protractor or photo app. Convert degrees to pitch: 18 degrees is about 4/12, 27 is about 6/12, 34 is about 8/12, 40 is about 10/12, 45 is 12/12.
- Phone apps from the ground. Some apps let you line up the roof edge in the camera and read the angle. Accuracy depends on standing square to the roof.
- House plans or permit records. Builders' plans usually label pitch on the elevations. Your county may have plans for newer homes.
- Aerial measurement report. Roofers and insurers order these; ask for a copy after an inspection or claim.
Quick visual estimate
- Looks almost flat: under 3/12.
- Gentle, easy to imagine walking: 4/12 to 6/12.
- Clearly steep, A-frame feel: 8/12 and above.
Different slopes, different pitches
Many houses have a steep front and a lower rear or porch roof. Measure each section you care about.
For the math behind the numbers, see how roofers measure a roof, and for what pitch means for materials, roof anatomy explained.