Who we are
Free Solar Calculator (free-solar-calculator.com) is an independent web tool focused exclusively on rooftop solar in India. We are not a solar installer, not an EPC company, and not a bank. We do not sell, install, or broker solar equipment — which means our numbers are never shaped by a sales quota.
Our users are homeowners planning their first rooftop system, buyers comparing quotes from installers, and professionals who need quick sizing references for proposals.
What we offer
- Sizing calculator — estimate plant capacity in kW from your monthly bill, units consumed, or roof area.
- PM Surya Ghar subsidy estimator — central subsidy slabs up to ₹78,000 under the PM Surya Ghar: Muft Bijli Yojana.
- 25-year savings & ROI model — bill savings, payback period, and lifetime returns with degradation and tariff escalation.
- Solar loan EMI calculator — compare loan tenure and EMI against self-funding at typical bank rates.
- State tariff & sun-hour data — DISCOM tariffs and peak sun hours for 36 states and union territories.
- Appliance load builder — build a load profile from your actual appliances instead of guessing from a bill.
How our calculations work
Every calculation runs in your browser using published reference data: MNRE benchmark costs for grid-connected rooftop systems, regional solar irradiation (peak sun hours per state), typical performance ratios (0.75–0.80), and average DISCOM tariffs. Where a scheme or benchmark changes, we update the underlying figures.
Results are indicative estimates for planning — not a quotation, an engineering report, or a guarantee of generation. Actual output depends on shading, roof orientation, panel choice, inverter sizing, and your DISCOM's net-metering policy.
Our principles
- 100% free — no paywalls, no premium tier, no email gate.
- No registration — there is no account system and no login of any kind.
- No spam calls — we never sell or share your details with installers, lenders, or lead generators.
- Transparent — assumptions behind every number are stated on the page itself.
Who it is for
Anyone evaluating rooftop solar in India — homes under 1 kW to large residences, housing societies, shops, offices, and installers preparing customer proposals. The tool works the same on a phone as on a desktop, and nothing you enter leaves your device.
Disclaimer
Information on this site is provided for general informational purposes only and does not constitute professional financial, legal, or engineering advice. Government subsidies, tariffs, and benchmark costs change frequently; always verify current figures with MNRE, your state DISCOM, or a licensed solar vendor before making a purchase decision. See our Terms & Conditionsfor the full disclaimer.