Slope is defined as a roof’s vertical rise (in inches) per foot of horizontal run (Slope vs. Pitch, below). For example, a 6:12, or “six-in-twelve,” roof rises 6 in. for every ft. of run.
Slope = Rise/Run
Pitch is different from slope; it’s the ratio of rise to span. For example, a roof sloped at 6:12 has a pitch of 1/4.
Pitch = Rise/Span
Note: Many building professionals use the Construction Master to solve roof framing calculations, and this tool uses "Pitch" when that button should read "Slope."