Terms of the Trade: What Is Roof Pitch? Terms of the Trade: What Is Roof Pitch?
Roof pitch is a measurement of the sloping angle of a roof. It's calculated by dividing the vertical rise by the horizontal span. (You may remember this from geometry class where it's called slope, or from trigonometry where it's called the tangent function.) Using the calculation, roofs are classified in ranges from "flat" and "low slope" to "conventional" and "steep-slope."