Glossary: Roof Pitch
**Roof Pitch** is the steepness of a roof slope, traditionally expressed in the United States as the vertical rise in inches per 12 inches of horizontal run (e.g., 4-in-12 or 4:12 pitch).
Roof Slope Conversions
Pitch determines rafter lengths and roofing material specifications. Low-slope roofs (under 2:12) require membrane sheets, whereas steep pitches permit asphalt shingles or metal panels.