How roof sizing works
Effective area = roof sq ft × usable %. Max panels = floor(effective area ÷ panel footprint). System kW = panels × panel watts ÷ 1,000.
Planning tips
Leave walkways for maintenance and comply with fire setbacks. Pair with Solar Panel Size to match daily energy needs.
Frequently asked questions
Q: What panel size should I use? A: Measure one module or use ~20 sq ft for modern 350–450 W panels. Q: Is every square foot usable? A: No—80% is a common planning factor.