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Boat Loan Calculator

This boat loan calculator turns a price, down payment, rate, and term into a monthly payment, then totals the interest and the overall cost of the boat.

The lowest rates are only available to the most qualified applicants.

Advertising disclosure: Loancalculated may receive a referral fee if you apply through the link above. That fee does not change the rate you are offered, and it does not change our content. We are not a lender. Read the full disclosure.

By the Loancalculated Editorial Team · Last updated 2026-09-16

Enter your numbers and press Calculate. Nothing you type leaves your browser.

Compare personal loan offers Run the numbers first

The lowest rates are only available to the most qualified applicants.

Advertising disclosure: Loancalculated may receive a referral fee if you apply through the link above. That fee does not change the rate you are offered, and it does not change our content. We are not a lender. Read the full disclosure.

How this calculator works

A boat loan is usually a fixed-rate installment loan secured by the vessel. The amount financed is the price minus your down payment.

Payment = P × i ÷ (1 − (1 + i)−n)

Total interest = payment × n − P, and the total cost adds the down payment back in. If the down payment covers the price, nothing is financed and the payment is zero.

Marine lenders price on loan size, boat age, and credit, so enter the rate you were quoted.

Frequently asked questions

How is the amount financed worked out?
The boat price minus the down payment you enter. The tool then amortizes that balance over the term at the rate you provide.
Do boat loans use the same math as car loans?
Yes. Both are fixed-rate installment loans, so the payment comes from the standard amortization relationship.
Why does a longer boat loan term cost more?
The balance is spread over more months, so the payment drops, but interest is charged for longer and the total climbs.
What rate should I enter?
The rate from your own offer or one you want to test. Marine loan pricing varies by lender, boat age, and credit profile.

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