Solar Rooftop Area Calculator
Measure your roof, estimate the usable share and see how many panels could fit.
Typical shadow-free share is often well below 100%.
Assumptions and formulas
Usable area = length x width x usable %. Capacity = usable area / 10 m² per kW. Panels = capacity / 550 W, rounded down. Allow for water tanks, stair rooms, parapet shadows and walkways in the usable %.
Disclaimer: results are illustrative estimates based on the assumptions above, not a quotation or guarantee. Actual generation depends on your site, shading, season and equipment.
Estimating usable area
Subtract areas lost to tanks, stair rooms, parapet shadows, walkways and obstructions. Many roofs usable share is well below the full footprint.
Flat versus sloped
Flat roofs use tilted frames needing spacing between rows, so they need more area per kW than flush-mounted sloped roofs.
Frequently asked questions
Are these results a quotation?
No. They are illustrative estimates from the stated assumptions.