Financing

15-year solar loan calculator

Enter your loan amount and APR. See the monthly payment and total interest on a 15-year term, plus how that payment compares to your expected bill savings.

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2 Your loan
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How it works

Three steps to your 15-year loan numbers

Step 1

Get your loan amount and rate

Use the loan amount after any down payment and your quoted APR. The loan term comparison tool shows this term next to 10, 20, and 25 years if you're still deciding.

Step 2

Check the payment against your budget

A 15-year term sits between the shortest and longest common terms, offering a middle-ground monthly payment.

Step 3

Add your bill savings for a full picture

Entering your expected monthly savings shows whether the loan payment leaves you cash-flow positive or negative each month. The 10-year loan calculator shows the same comparison at a shorter, higher-payment term.

Reading your 15-year loan result

Why 15 years is often called the middle-ground term

A 15-year term pays off faster than 20 or 25-year loans while keeping the monthly payment more manageable than a 10-year term. On a $28,000 loan at 6.99% APR, the 15-year payment runs about $252 a month, with total interest around $17,273, positioned squarely between the shorter and longer term options. The CFPB's explainer on how loan amortization works covers why term length affects total interest this much.

What that middle ground actually costs versus a 10-year term

Choosing 15 years over 10 years lowers the monthly payment by about $73, but adds roughly $6,278 in total interest over the life of the loan. That's the direct tradeoff: a more comfortable monthly payment in exchange for a higher overall cost. The solar payback period calculator can help you see how that extra interest cost factors into your overall payback timeline.

How it compares against going longer instead

Stretching to a 20-year term drops the payment further, to around $217 a month, but adds close to $6,787 more in total interest compared to 15 years. Run the 20-year loan calculator alongside this one to see whether that additional flexibility is worth the extra cost for your situation.

Who tends to choose a 15-year term

This term fits well for someone who has some room in their budget beyond their expected bill savings and wants to be debt-free on the system sooner than a 20 or 25-year term would allow, without taking on the highest monthly payment available. The monthly budget fit calculator can help confirm the payment fits comfortably before committing. Rebates and tax credits change what you actually borrow. The sales tax exemption savings calculator in our Rebates & Incentives section estimates what you can claim before you sign a loan.

What to check before locking in any term

Confirm whether your lender charges the same APR regardless of term, since some lenders price shorter terms slightly better. The loan APR impact calculator shows how much even a small rate difference matters once compounded over 15 years. The CFPB's issue spotlight on solar financing covers general financing considerations worth reviewing before signing.

Questions

Frequently asked

On a $28,000 loan at 6.99% APR, a 15-year term runs about $252 a month, landing between the roughly $325 a month for a 10-year term and $217 a month for a 20-year term at the same rate. Total interest comes to about $17,273 over the 15-year term.

Yes, a 15-year term is often described that way because it saves meaningfully on interest compared to 20 or 25-year terms while keeping the payment more manageable than a 10-year term. It's a reasonable default for someone who wants faster payoff without the highest possible monthly payment.

On a $28,000 loan at 6.99% APR, a 15-year term costs about $17,273 in total interest compared to about $10,995 for a 10-year term, a difference of roughly $6,278. That's the cost of the lower monthly payment the 15-year term provides.

It often runs slightly higher than typical bill savings, similar to a 10-year term but with a smaller gap. A $252 monthly payment against $125 a month in typical savings still leaves a real difference, which is why many solar loans default to 20 or 25-year terms to close that gap more completely.

Related tools

Keep comparing your financing options

Loan term comparison tool 10-year loan calculator 20-year loan calculator Total interest paid calculator Loan APR impact calculator Early payoff savings calculator Amortization schedule generator All financing tools