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Solar calculators
Free tools for sizing, pricing and checking a solar system. No sign-up, and every result is an estimate you can check against our price lists.
01Off-grid system calculatorSize panels, battery, inverter and charge controller from your daily use, then price the build with real best-value Amazon parts, as separate parts or an all-in-one.02Solar savings calculatorWhat solar saves on your electric bill by state: monthly, yearly and over 25 years with rate increases.03Solar ROI calculatorSystem size, net cost after the tax credit and state incentives, payback period and 25-year return.04Solar financing calculatorCash vs. loan vs. lease or PPA over 25 years, with the true cost of each option.05Shade loss calculatorProduction lost to roof shade, and whether microinverters or optimizers pay for themselves.06Tilt angle calculatorThe best panel tilt for your state and how much your roof pitch and direction cost you.07String sizing calculatorThe maximum safe number of panels per string, corrected for your state’s coldest day.08Panel technology selectorTOPCon vs. HJT vs. IBC vs. PERC: which cell technology fits your climate, roof and budget.