Boat Loan Calculator
Calculate your monthly boat loan payment and total interest from the vessel price, down payment percentage, marine loan APR, and term. Taxes, fees, and insurance are excluded.
How It's Calculated
Formula
\text{Financed Principal} = \text{Vessel Price} \times (1 - \text{Down Payment \%})\\ \text{Payment} = \dfrac{P \times r \times (1 + r)^n}{(1 + r)^n - 1}This calculator estimates your monthly boat loan payment. It first works out your financed principal — the vessel price minus your cash down payment — then applies the standard fixed-rate amortization formula using your marine loan APR and term, the same math used for auto loans and mortgages. This estimate excludes sales tax, registration, documentation fees, insurance, and marina costs — all of which vary by state and lender and are not modeled here. If you plan to finance any of those costs into the loan itself, add them to the vessel price before entering it.
Worked Examples
$50,000 vessel, 20% down, 7% APR, 10-year term
- Down payment = $50,000 × 20% = $10,000.00; financed principal = $50,000 − $10,000 = $40,000.00
- periodicRate r = 0.07 / 12 ≈ 0.0058333; n = 10 × 12 = 120 payments
- Monthly payment = 40000 × r × (1+r)^120 / ((1+r)^120 − 1) ≈ $464.43
$24,000 vessel, 0% down, 0% APR, 2-year term
- Financed principal = $24,000.00 (no down payment)
- With 0% APR, the payment is a straight-line division: $24,000 / 24 payments = $1,000.00/month
- Total interest = $0.00
Frequently Asked Questions
Does this include sales tax or registration fees?
No. This calculator estimates the loan payment on the financed principal only — sales tax, registration, documentation fees, insurance, and marina costs are all excluded and vary by state and lender. If you're financing any of these into your loan, add them to the vessel price before entering it here.
What if I make a 100% down payment?
A 100% (or greater) down payment leaves nothing to finance, so this calculator treats it as an invalid input for a loan calculation rather than showing a $0 payment — if you're not financing any amount, there's no loan to calculate.
Are marine loan rates different from auto loan rates?
Often yes — marine loans can carry different rates, terms, and lending criteria than auto loans, partly because boats depreciate differently and loan terms can run longer. Enter the actual APR quoted by your marine lender, not an auto loan rate.
Can I use this for a used boat?
Yes — enter the actual purchase price of the vessel, new or used. The amortization math is the same either way; only the interest rate and loan terms your lender offers might differ for a used vessel.