Run (horizontal distance)
Rise (vertical distance)
Result (click to copy)
Frequently Asked Questions
What is roof pitch?
Roof pitch is the slope of a roof expressed as a ratio of vertical rise to horizontal run, typically per 12 inches of run. A 6:12 pitch means the roof rises 6 inches for every 12 inches of horizontal run. Steeper pitch = higher number.
What is a standard roof pitch?
Common residential pitches: 4:12 to 6:12 (moderate). Low pitch: 1:12 to 3:12. Steep: 7:12 to 12:12. Very steep: over 12:12. Most roofing materials work on pitches of 4:12 and above. Flat roofs use special waterproofing membranes.
What is the slope multiplier?
The slope multiplier converts horizontal (flat) measurements to actual roof surface measurements. A 6:12 pitch has a multiplier of 1.118, meaning the actual roof area is 11.8% larger than the floor area below it.