Indicative rooftop solar planning
Rooftop Solar Size & Savings Calculator
Estimate solar capacity from monthly electricity use, sun hours, performance ratio, roof area and user-entered tariff.
Your result
Enter measured or nameplate values to calculate.
- Usage-matched capacity
- —
- Roof-area limit
- —
- Indicative generation
- —
- Approx. panel count
- —
- Energy-value ceiling
- —
Method
Usage-matched kW = monthly kWh ÷ (30 × peak-sun-hours × performance ratio). Roof limit and panel count are shown separately; savings cannot exceed entered grid-energy value.
Important limits
Indicative only. Do not hard-code subsidy, export credit or price. Shading, orientation, structural capacity, inverter limits, DISCOM rules and site survey can change the result.
Technical reference
Estimate rooftop solar capacity, panel count, annual generation and electricity savings from usage, roof area and yield.
What to enter
Use current, project-specific values for electricity usage, usable roof area and expected yield. Check every unit before calculating and compare like-for-like inputs. The template controls the actual fields and calculations; this supporting copy does not replace its labels, formulas or result logic.
How to use the result
Treat capacity, panel count, generation and savings as estimates. Roof layout, shading, orientation, tariffs, approvals and equipment performance require site-specific checks.
Before making a decision
Verify source measurements, equipment specifications and operating conditions. Have a qualified professional review the final selection, safety and installation requirements before purchase, connection or construction.