Rooftop Solar Calculator

Get an instant size, cost and payback estimate tuned for Punjab, Himachal Pradesh and Jammu & Kashmir. All math runs in your browser — nothing is sent to our servers.

Tell us about your usage

Your state We use region-specific Peak Sun Hours so the estimate reflects your local sunlight, not a national average.

How do you want to estimate?

Monthly bill (₹) Monthly units (kWh)

Average monthly bill (₹)

Tariff (₹ per unit) Auto-fills from your state. Override with your actual slab rate for a sharper estimate.

System type Not sure? See the systems comparison page.

Your estimate

Enter your details and tap Calculate.

How this works. Required size (kW) = daily units ÷ (Peak Sun Hours × performance ratio). We assume a 78% performance ratio (industry standard, after inverter/wiring/soiling/temperature losses), ~100 sq ft of unshaded roof per kW, and a 25-year panel life. Estimates are indicative — actual generation depends on shading, orientation, equipment grade and your local DISCOM tariff. Get in touch for a site survey and detailed engineering proposal.