Frequently Asked Questions

Yes — completely free, with no sign-up, no email gate, and no contact form standing between you and your result. You get your estimate instantly, and we never pass your details to installers or sell your data.

They use the same industry-standard formulas professionals rely on, and every tool shows its working. They give you a reliable ballpark for planning and comparison. A final system design still needs an on-site assessment that accounts for your specific roof, shading, wiring and local rules — no online tool can replace that.

Yes. You can set your own electricity rate, currency and sun-hours, so the engineering and savings tools work anywhere. We also have country-specific calculators for the USA, India, Australia, Germany, Pakistan, the UK and South Africa that build in each country's subsidies and tariff rules.

Two common reasons. First, many calculators haven't updated for recent policy changes — for example, the US residential federal tax credit ended for owned systems after 2025, yet some tools still apply it, which inflates savings and shortens payback. Second, installer quotes sometimes value all your solar at the full retail rate, when in reality exported power is often paid much less. We try to reflect current rules and separate self-use from export. Always confirm the latest policy before you buy.

Sun-hours are based on public satellite irradiance data (for example, NASA POWER for our India district figures). Tariffs, subsidies and scheme rules are drawn from official sources and dated in each tool. Because these change by government notification, we label them with a "verify current rates" note and let you edit the values to match your own bill.

The calculations run in your browser. We don't require an account and don't collect the figures you type to perform a calculation. We do use standard analytics and advertising tools on the site — see our privacy policy for details.

We verify them against official and reputable sources and date them, but schemes change — and the most volatile ones (like the US federal credit) can shift again. Treat our figures as a well-researched starting point, then confirm the current rules with the official portal or your bank/utility before making a decision.

Through advertising and affiliate links, not by selling your data or generating sales leads for installers. That model is what lets us stay independent and avoid the "enter your phone number to see results" pattern. See our privacy policy for how ads and affiliates work here.

No. We deliberately avoid naming inverter or panel brands or steering you to particular installers. Our job is to give you honest numbers so you can have a better-informed conversation with whichever installer you choose.

We'd genuinely like to hear it. Email us at contactus@prosolarcalc.com or see the contact page.