How to Measure Roof Pitch

Four accurate methods to measure your roof pitch — from the roof, from the attic, from the ground, and with a speed square.

1. On the Roof

Most accurate — directly on the slope

Need safety equipment

2. From the Attic

Safest method — no need to climb

Good for most homes

3. From the Ground

Approximate — using photos

Totally safe

4. Speed Square

Quick angle reading with the tool

For pros

Method 1: Measure From the Roof

⚠️ Most accurate but requires safety equipment. Use a harness on steep roofs.

1. Safely climb onto the roof using a proper ladder secured to the eave.
2. Place a 2-foot (24") level flat on the roof surface, with one end touching.
3. Lift the free end until the bubble centers — this means it's perfectly level.
4. Measure 12 inches along the level from the touching end.
5. At the 12-inch mark, measure straight down (vertically) to the roof surface.
6. That vertical measurement is your rise. Your pitch is rise/12.

Example: If the vertical distance measures 6 inches, your pitch is 6/12 — a very common residential pitch.

Method 2: Measure From the Attic

✅ Safer — no climbing onto the roof. Works if you have attic access.

See the full step-by-step guide on the attic measurement page.

Method 3: Measure From the Ground

✅ Totally safe but only an approximation. Good for quick estimates.

See the ground measurement guide for the photo-trigonometry method.

Method 4: Speed Square

⚡ Fastest method if you have the tool — reads the angle directly.

See the speed square guide for the technique.

After Measuring

Once you have your rise/run values, plug them into our Roof Pitch Calculator to get pitch ratio, angle in degrees, slope percentage, and material recommendations.