Solar Roof Calculator
Calculate your usable roof area for solar panels, maximum system size, and estimated annual energy production based on roof dimensions, pitch, orientation, and shading.
Horizontal length of the roof section
Horizontal width of the roof section
Typical residential: 20-35 degrees
Direction the roof face points
Percentage of roof shaded by trees/buildings
Typical: 18-22%
Frequently Asked Questions
What roof pitch is best for solar panels?
The ideal roof pitch for solar is typically between 25-35 degrees in the US, roughly matching your latitude. However, solar panels perform well between 15-45 degrees. Flat roofs can use tilted mounting systems to achieve optimal angles.
Does roof orientation matter for solar panels?
Yes, significantly. South-facing roofs in the Northern Hemisphere produce the most energy (100%). Southwest and southeast produce about 94%, west and east about 82%, and north-facing roofs only about 55% of maximum output.
How much roof space do I need for solar panels?
A typical residential solar panel (400W) requires about 17.5 sq ft. For the average US home needing a 7-8 kW system (about 20 panels), you need roughly 350-400 sq ft of usable, unshaded roof space.