Roof Pitch Calculator — Angle, Multiplier & Grade

Rise and run in — pitch per 12, roof angle in degrees, the area multiplier and percent grade, all at once.

Roof Pitch Calculator

The three ways roofers say pitch

The same roof is described three ways: <strong>pitch per 12</strong> (6/12), <strong>angle in degrees</strong> (26.6°), and <strong>percent grade</strong> (50%). Enter any rise and run and the calculator converts between all of them, plus the area multiplier that turns a flat footprint into actual roof surface for ordering.

Why the multiplier matters for ordering

The multiplier is how much bigger the sloped roof is than the footprint. A 6/12 roof multiplies by 1.118, a 12/12 by 1.414 — forget it and you order three squares short on a simple gable. Every material calculator on this site that takes a pitch asks for the multiplier this page produces.

FAQ

What pitch is a 45-degree roof?

12/12 — the roof rises 12 inches per 12 inches of run, a 100% grade, with a 1.414 area multiplier.

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