Roof Pitch Calculator
Calculate roof pitch from rise and run. Get pitch ratio, angle in degrees, and area multiplier. Essential for roofing contractors.
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How Pitch Calculations Work
Pitch = Rise / Run
Standard pitch ratio (e.g., 6/12)
Angle = arctan(Rise / Run)
Angle in degrees from horizontal
Multiplier = √(1 + (Rise/Run)²)
Hypotenuse multiplier for area
Roof pitch is expressed as rise over run - the vertical rise in inches for every 12 inches of horizontal run. A 6/12 pitch rises 6 inches for every 12 inches horizontally.
The area multiplier is crucial for roofing estimates. Since the roof is sloped, its actual surface area is larger than the building footprint. Multiply the footprint area by this multiplier to get the true roof area.
For example, a 6/12 pitch has a multiplier of 1.118, meaning a 1,000 sq ft footprint becomes 1,118 sq ft of actual roof surface.
Reference: National Roofing Contractors Association (NRCA) guidelines