How to Measure Roof Pitch for Solar Panels

Here are instructions to measure the roof pitch or slope for solar panels. The pitch will impact the amount of tilt toward the Sun for the PV array. Most arrays are flush-mounted, meaning they follow the same pitch as the roof, but are raised a few inches above. There are times with flat or nearly flat roof, or to improve Sun exposure, that additional tilting is desired.

To measure the pitch of a roof, all that is needed is a tape measure, pencil, paper and some common sense. These instructions will guide you through the process. If you need help we offer PROFESSIONAL SOLAR DESIGN SERVICES.

Roof pitch or slope refers to the amount of vertical rise a roof has relative to 12 inches of the horizontal run measurement. The illustration shows the pitch of a 7:12 roof slope, meaning that the vertical rise measurement (roof rise) is 7" and the horizontal run measurement (roof run) is 12". Using the illustration, you can see that a 7:12 roof pitch has a 30 degree angle.

Now that you understand the fundamentals of roof pitch, this measurement can be used to determine the angle of your roof pitch in degrees for a solar panel installation. If the roof is flat or nearly flat, it may be desired to tilt the solar panels on the roof to achieve optimal angle toward the Sun. The PV mounting system can often include standoffs of various heights to increase tilt.

Common Pitched Roof Angles

The illustrations below depict common roof pitches and their angle degrees for quick reference in identifying your roof. This information will be used by the solar installer or when choosing the mounting rack components. For more information visit how to measure a roof for solar panels.

1:12 pitch 5° angle	2:12 pitch 9.5° angle	3:12 pitch 14° angle	4:12 pitch 18.5° angle
5:12 pitch 23° angle	6:12 pitch 27° angle	7:12 pitch 30° angle	8:12 pitch 34° angle
9:12 pitch 37° angle	10:12 pitch 40° angle	11:12 pitch 42.5° angle	12:12 pitch 45° angle