Solar calculators
Free solar calculators that explain the math
Solar calculator, panel count, payback, EV charging, quote comparison and state-by-state checks. No accounts; calculations run in your browser. Site usage analytics are described in our privacy policy.
Solar calculator
Bill, electric rate and quote price in — system size, panel count, gross cost and simple payback out. Built for high-intent calculator searches.
bill + quote→size + paybackHow many panels?
Turn monthly usage into panel count, roof area and system size with one honest rule-of-thumb model.
usage→panel countPayback calculator
Enter net cost, savings and annual changes — compare simple payback with year-by-year cash flow.
cost + savings→break-evenQuote scorecard
Compare up to three cash quotes by $/W and relative price differences. Match scope; price is not a quality grade.
3 quotes in→best $/W outSun look-up
ZIP in, measured 2024 sunshine out — a 12-month curve for your state, then a rough model of what a roof would make of it.
1 ZIP code→12-month curveIs solar right for me?
Ten questions, one scored verdict — the 60-second first-pass before you call an installer.
10 answers→a clear verdictBuyer checklist
A one-page, printable checklist of the questions and numbers worth having before you sign anything.
16 questions→signed without regretSREC income calculator
Certificate markets (SREC/TREC, SMART, Shines) by state — size your system, type today's price, see the 10-year income math.
price + size→10-year incomeAll 50 states, compared
Sortable, filterable table of all 50 states — measured sun, resource zone, facts depth and verification date in one view.
50 rows→any orderEV charging cost calculator
Miles, efficiency and electric rate in — monthly kWh, home charging cost and gasoline comparison out.
miles + rate→EV costSolar panels for EV charging
Estimate how many extra solar panels it takes to cover an EV's annual charging load at home.
EV miles→panels neededHome charger time estimator
Battery size, target charge and Level 1/2 power in — charging hours and daily miles recovered out.
battery + kW→hoursBattery size planner
Enter your bill and export-credit situation — see what battery size would actually cover, with honest economics.
bill + export→kWh sizedA sane order to use them
Sales calls reverse this sequence on purpose. Don't let them.
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