Solar Panel Optimal Tilt Angle
Calculate the optimal solar panel tilt angle for year-round, winter, and summer conditions based on your geographic latitude.
Results
What is it?
Solar panels generate the most electricity when sunlight hits them at a 90-degree angle. Because the sun's path varies with the seasons, the optimal tilt angle changes throughout the year. The general rule of thumb: year-round tilt equals your latitude, winter tilt equals latitude + 15 degrees, and summer tilt equals latitude - 15 degrees.
How to use
Enter your latitude in decimal degrees (positive for Northern Hemisphere, negative for Southern). The calculator shows the recommended panel tilt angles for three scenarios. If your panels have adjustable mounts, change the angle seasonally. For fixed-mount systems, use the year-round angle.
Example scenario
A homeowner in Sydney, Australia (latitude -33.9 degrees) uses abs(-33.9) = 33.9 degrees. Year-round tilt: 34 degrees. For maximum winter gain (June in Australia): 34 + 15 = 49 degrees. For summer: max(34 - 15, 0) = 19 degrees. Adjusting twice a year can increase annual yield by 5�10%.
Pro tip
In practice, roof pitch often dictates the actual tilt angle. A flat-mounted panel that matches your roof slope may be within a few degrees of optimal. For ground-mount systems, dual-axis trackers can increase yield by 25�40% over fixed panels, but add significant cost and maintenance overhead.