Rooftop Area to Solar kW Calculator
Estimate how much rooftop solar capacity may fit on your roof area based on usable area, roof type, shading, and practical rooftop planning assumptions.
Estimate solar kW from rooftop area
Enter your roof area, choose the unit, and adjust for roof type, shading, and usable area. This makes the estimate more realistic than using total roof size alone.
Enter the approximate rooftop area available for solar planning.
Choose whether your rooftop area is in square feet or square meters.
Different roof types can change how efficiently panels can be arranged.
Use this to account for nearby buildings, trees, tanks, or other partial roof shading.
Optional. Override the default usable roof percentage if you have a better estimate of clear shadow-free area.
How much roof area is needed for solar
- We first convert your rooftop area into a common unit and reduce it using the usable-area percentage, roof type, and shading assumptions.
- We then divide the effective usable area by the shared area-per-kW assumption to estimate how much solar capacity may fit.
- Finally, we estimate monthly generation, yearly generation, and indicative savings to help you judge whether the rooftop looks promising before a real survey.
Rooftop area to solar kW FAQ
This section can later answer questions about area per kW, shadow-free space, tanks and parapets, roof shape, and why two roofs of the same size may support different solar capacities.
Your rooftop solar capacity estimate
These results help you understand approximate installable kW, likely solar generation, savings potential, and how structure or shading can reduce the practically usable rooftop area.
Approximate installable solar capacity
0 kW
The estimated solar kW your rooftop may practically support after adjustments.
Estimated monthly generation
0 units
Expected monthly solar generation under shared planning assumptions.
Estimated yearly generation
0 units
Approximate yearly solar output from the installable rooftop capacity.
Indicative savings potential
Rs 0
A directional monthly savings estimate based on the generation output.
Usable area note
Waiting for inputs
A practical note on how much of your entered rooftop area may actually be usable for solar.
What this means
Not all roof area is usable for solar. Setbacks, water tanks, access paths, parapet shadows, tilt spacing, and roof shape can reduce effective panel area. This estimate gives a planning-level capacity range before an actual site survey.
Want a real rooftop site survey?
Connect with verified solar vendors to check shadow-free roof space, panel layout, and the actual solar kW your rooftop can support.
Book a Solar Site SurveyRooftop estimate disclaimer
Actual installable solar capacity depends on roof dimensions, access spacing, structural conditions, shadow-free area, tilt layout, local setbacks, and installer design choices. Use this as a directional estimate only.