Free, instant, no signup. Solve for payback period, system size, battery storage, and 25-year savings — with real ingredient-level math, not generic "solar pays for itself in 7 years" handwaving.
How many years until your panels pay for themselves — with inflation, tax credits, and the real math.
What size system (in kW) actually covers your bill, accounting for sun hours and roof efficiency.
How much battery you need for backup hours, daily cycling, or full off-grid.
Exactly how much you'll get back from the IRA tax credit, with state rebate stacking.
Total return on your solar investment over 25 years vs. paying the grid.
How much extra system you need to power your electric vehicle from sunlight.
Most solar calculators online are lead-capture forms in disguise. They ask you for your phone number, send your data to 6 installers, and never actually show you the math.
SolarSavingsMath does the opposite: real calculators, real numbers, no signup, no lead capture. If you eventually want quotes from installers, we'll point you to honest options. But first, you should know the math.
Every formula on this site is open. We cite NREL, EIA, and IRS as primary sources. If a number looks wrong, tell us and we'll fix it.