About SmartSolarSizer
Most solar calculators ask for one number — your monthly bill — and hand back a system size with no way to see how it was arrived at. That's fine if all you have is a bill. But if you're starting from "I want to run my AC and fridge on solar," working backward from a bill figure you don't have yet isn't very useful.
SmartSolarSizer starts from wherever you actually are. Know exactly what's running in your house? Add it appliance by appliance and get an inverter and array size built from real running and surge loads. Only have your electricity bill? Use that instead. Either way, you get the same depth of result: panel count, inverter rating, upfront cost, and a real year-by-year payback projection — not just a single ballpark figure.
Built on real formulas
Every number traces back to a standard, published sizing formula — nothing is a black box. Our payback guide walks through the math directly.
No sign-up, no data collection
The calculator runs entirely in your browser. We don't ask for an account, and nothing you calculate is sent anywhere unless you choose to request installer quotes.
Built for anywhere
Regional sun-hour presets and multi-currency support mean the same tool works whether you're sizing a system in Lahore, London, or Los Angeles.
What we're not
We're not a solar installer, and we don't sell equipment. When you use the "Get quotes" option, you're opting in to be contacted by third-party installers — SmartSolarSizer itself doesn't install anything. Every result on this site is a planning-stage estimate, not an engineering design; see our Terms of Service for the full disclaimer.