Roof pitch is a measure of how much a roof rises in relation to its span. In other words, roof slope is the angle of a roof’s surface relative to the horizontal plane. What you’ll often see referred to as pitch is technically the slope. Here’s the difference: slope is measured as the rise over run, while pitch actually refers to the rise over span (where span is the entire horizontal measurement of the roof, and therefore equals twice the run). You’ll often find the terms “pitch” and “slope” used interchangeably in the roofing industry however, there is a distinction as they refer to two different measurements.
