ROOF PITCH
ROOF PITCH
pitch = (rise × 12) ÷ run
in
in
RESULT
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FILL IN ABOVE
Measure rise at exactly 12 inches of run for the trade format. Pitches below 2/12 require membrane roofing. Below 4/12 needs ice and water shield in cold climates.
About this calculator
This roof pitch calculator converts a measured rise and run into the four ways pitch is expressed: the trade format (X in 12), the angle in degrees, the slope as a percentage, and the slope multiplier used to convert plan-view square footage into actual roof surface area for shingle ordering. Standard residential pitches run from 4/12 (low) through 12/12 (steep). Anything under 2/12 is considered low slope and needs a membrane roof, not asphalt shingles.