Boat Loan Calculator: Monthly Payment on a Marine Loan
Work out the monthly payment and total interest on a loan for a boat, where the vessel secures the loan and terms can stretch well beyond a decade.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year amortization schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Monthly payment | Total interest | Total of payments |
|---|---|---|---|
| $45k · 7.8% · 10-year | $541.23 | $19,947.62 | $64,947.62 |
| $20k · 8.5% · 7-year | $316.73 | $6,605.30 | $26,605.30 |
| $90k · 7.2% · 15-year | $819.04 | $57,427.57 | $147,427.57 |
| $30k · 9.0% · 8-year | $439.51 | $12,192.59 | $42,192.59 |
How This Calculator Works
Enter the amount financed — the boat price after any down payment and trade-in — the APR, and the term. Marine loans are secured by the boat and are often written over ten to twenty years for larger vessels. The calculator turns the APR into one constant monthly payment and shows the falling balance year by year.
The Formula
Fixed-Rate Amortization
P = loan amount, r = monthly rate (APR ÷ 12), n = number of monthly payments
Worked Example
Financing $45,000 for a boat at 7.8% APR over 10 years gives a monthly payment of about $541. Over the loan you repay roughly $65,000, so interest adds close to $20,000 to the amount you financed.
Key Insight
Lenders often require a marine survey and proof of insurance before approving a boat loan, and they price older or larger vessels more cautiously. A solid down payment improves both the rate offered and your equity position from day one.
Frequently Asked Questions
Is a boat loan secured?
Usually yes — the boat is the collateral. That keeps the rate below unsecured borrowing, but the lender can repossess the vessel if the loan is not repaid.
What term can I get on a boat loan?
Terms range widely, from a few years for a small boat to twenty years for a large vessel. A longer term lowers the monthly payment but raises total interest considerably.
Will I need a marine survey?
For many boats, especially used or higher-value vessels, lenders require a marine survey to confirm the boat's condition and value before approving the loan.
What counts as the amount financed?
Enter the purchase price after your down payment and any trade-in. Some lenders also let you roll in taxes, registration, or outfitting costs.
Does boat insurance affect the loan?
Lenders generally require proof of insurance for the life of a secured boat loan. Insurance is a separate cost and is not part of the payment this calculator shows.
Related Calculators
Data Sources & Benchmarks
This calculator draws on 3 independent, dated sources. The starting values for interest rate are taken from the benchmarks below and refresh whenever the snapshots are updated.
Methodology & Review
Payments use the standard fixed-rate amortization formula. The calculator assumes a fixed APR on the amount financed and excludes insurance and survey costs, which are paid separately.
Written by Ugo Candido · Last updated May 17, 2026.