Solar calculator

Type what you pay each month. Everything else is on the table below the results, with the source it came from. If a value has not been verified, the calculator tells you.

One question at a time

The same engine, the same data, a single answer put first. Nothing below computes anything the calculator above does not — which is the point: two calculators on this site cannot disagree, because there is only one.

• Solar panel size calculator

  How many kilowatts, how many panels and how much roof, from your bill and your state.

• Solar panel cost calculator

  Installed price for your system on both price bases, and what is left after credits.

• Solar payback calculator

  The year your savings repay the system, and the curve that gets you there.

• Solar savings calculator

  What you keep over 25 years, and the bill you avoid each year on the way.

• Lease vs buy solar calculator

  Cash, loan and lease on the same house, with who keeps the federal credit.

• Solar battery calculator

  The same system with and without storage, side by side.

• Solar incentives calculator

  Federal, state and performance payments for your system, each with its source.