Roof Pitch / Roof Slope

Roof pitch (or roof slope) describes the steepness of a roof, typically expressed as a ratio of vertical rise to horizontal run — for example, a 6:12 pitch means the roof rises 6 inches for every 12 inches of horizontal distance. This ratio directly determines the tilt angle of roof-mounted solar panels.

Common residential roof pitches range from 3:12 (low slope, about 14°) to 12:12 (steep, 45°). A 6:12 pitch (about 27°) is one of the most common and happens to be close to optimal for solar in many US locations. Roof pitch affects solar production, installation methods, and safety requirements. Low-pitch roofs (3:12 or less) may benefit from tilted racking to increase the panel angle, while very steep roofs (10:12+) can pose safety challenges during installation and may require specialized equipment. The optimal pitch for solar depends on your latitude — as a general rule, a pitch equal to your latitude angle maximizes annual production. However, variations of 10–15° from optimal typically reduce production by less than 5%, so most roof pitches work well for solar. Your installer will account for your specific roof pitch when calculating expected system production.