Boat Loan Calculator

Boat financing doesn't work quite like a car loan. Marine lenders treat a boat as a secured recreational asset, and the terms they offer scale dramatically with the size of the loan. For example, a $15,000 runabout and a $250,000 cruiser are underwritten on completely different ladders.

Before you commit, check how this payment affects your debt-to-income ratio.

This calculator builds the full amortization schedule for a boat loan, tracks how much interest you'll pay over the life of the note, and charts the boat's depreciating value against your loan balance so you can see when you cross from negative into positive equity.

How does this calculator work?

Enter the boat's purchase price and the amount you're financing after your down payment and any trade-in. Marine lenders typically want 10–20% down, and larger loans usually require more equity up front.

Set the term and APR. It's a solve-for-any-field tool. Enter a target monthly payment instead of a loan amount, term, or rate and it back-solves the missing value, which is handy when you have a fixed monthly budget in mind.

Add an optional extra monthly payment to see how much faster the note retires and how much interest you avoid. Because boat loans often run 10–20 years on larger amounts, even modest extra principal compounds into real savings.

Set a depreciation rate to plot the boat's market value beside your loan balance. The crossover point shows when you'd no longer be underwater if you had to sell.

Worked example

Suppose you buy a $90,000 cruiser, put 15% down ($13,500), and finance $76,500 at 7.5% APR over 15 years.

Purchase price

$90,000

Down payment (15%)

$13,500

Amount financed

$76,500

Term / APR

15 yrs / 7.5%

Monthly payment

$709.16

Total interest

$51,150

How the numbers work

The $709.16 payment is the amortization result for $76,500 at 7.5%, or 0.625% per month over 180 months.

Because the term is so long, the first month's interest ($76,500 × 0.625% = $478.13) eats up most of the payment, leaving only $231.04 for principal. That slow early paydown, paired with the boat depreciating, is exactly what can keep you underwater for years.

Over all 180 payments you repay $127,650, which is the $76,500 borrowed plus $51,150 in interest.

Over 15 years you'd pay $51,150 in interest, which is two-thirds of the amount borrowed. Shortening the term to 10 years raises the payment to $908.07 but cuts total interest to $32,468, saving $18,681.

Because boats depreciate, the long 15-year term also keeps you underwater longer. The value chart makes that trade-off visible.

How marine lenders structure boat loans

Most boat loans are simple-interest installment loans secured by the vessel itself, much like an auto loan. The key difference is term length: lenders extend repayment far longer on big-ticket boats, with 15- and even 20-year notes common above six figures, because the longer term keeps payments affordable on an expensive asset.

Larger loans frequently require a marine survey (a professional condition and valuation inspection) and, for documented vessels, U.S. Coast Guard documentation rather than a state title. These requirements protect the lender's collateral and can affect closing timelines, though they don't change how the payment is calculated.

Can you deduct boat loan interest?

If your boat has a sleeping berth, a galley (cooking facilities), and a head (toilet), the IRS may treat it as a qualified second home, which can make the loan interest deductible as home mortgage interest. This is subject to the usual limits and only if the loan is secured by the boat. This is a meaningful difference from a car loan, where interest is rarely deductible for personal use. Tax rules change and depend on your situation, so confirm eligibility with a tax professional before counting on the deduction.