Solar Loan Calculator — Monthly Payment vs. Your Bill, 2026

See your monthly loan payment, total interest, and whether it beats what you're paying the utility today.

⏱ ~20 sec💳 Any term/rate🔒 No signup

Your loan

$176 /mo
Estimated monthly payment
Amount financed$15,120
Total interest paid$5,940
Total repaid$21,060
vs. current bill+$26 /mo

"vs. current bill" is payment minus your current bill — negative means the loan payment is already less than what you pay the utility today.

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Further reading: Cash vs. Loan vs. Lease vs. PPA: Which Solar Financing Actually Wins?

How the loan payment is calculated

Monthly rate r = APR ÷ 12 ÷ 100
Payment = P × r(1+r)^n ÷ ((1+r)^n − 1), where P = amount financed, n = term in months

This is the standard fixed-rate amortization formula banks use for any installment loan. It assumes equal monthly payments for the full term with no balloon payment — check your lender's actual terms, since some solar loans include a "step-down" once a tax credit is applied.

Frequently asked questions

Should the loan payment be lower than my electric bill?

That's the common target for a "cash-flow positive" solar loan — you replace a bill with a payment that's the same or smaller from day one, then keep the full savings once the loan is paid off.

How does a bigger down payment change things?

It lowers the amount financed, which lowers both the monthly payment and total interest — run a few down-payment percentages here to see the trade-off against your available cash.

Is this a solar finance calculator or a solar panel loan calculator?

Same tool — "solar loan calculator," "solar finance calculator," "solar panel loan calculator," and "solar financing calculator" all describe the same amortization math here: enter your system cost, down payment, APR and term to get the monthly payment, total interest, and total repaid for any solar financing offer.

Does this work for any lender's solar financing offer, not just a specific brand?

Yes — it's a generic fixed-rate amortization calculator, so it works for any bank, credit union, or solar-specific lender's loan terms. Just enter the APR and term from the actual offer you're comparing.

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