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Boat Loan Calculator

Monthly payment and total interest on a 10–20 year marine loan, with an optional balloon at the end and the fees rolled into the amount financed.

Boat Loan Calculator: with the default inputs, monthly payment is $555.87.

$
$
/ yr
years
of the loan
Try an example
Over 15 years the interest comes to $40,056 — about 67% of the amount financed. Boats depreciate throughout, so long terms mean years of owing more than the boat is worth.
Monthly payment
$555.87
Amount financed
$60,000
Balloon due at the end
$0
Total interest
$40,056
Total of payments plus balloon
$100,056
Total cost of the boat
$115,056
Interest as a share of the loan
66.8%
Interest in the first payment
$374.50
Loan-to-value at purchase
80%
Assumptions
  • Fixed rate, level monthly payments, simple interest on the declining balance.
  • The balloon is a percentage of the amount financed and falls due with the final payment.
  • Insurance, storage, maintenance and fuel are excluded — they typically exceed the loan payment.
  • Financed fees and taxes are added to the amount borrowed.
What you pay for
  • Boat (net of down payment)$60,00060%
  • Interest$40,05640%
Balance over time
$0$20k$40k147101315Year
Loan balance
Amortization by year
YearPrincipalInterestTotal paidBalance
1$2,253$4,418$6,670$57,747
2$2,427$4,243$6,670$55,320
3$2,616$4,055$6,670$52,704
4$2,818$3,852$6,670$49,886
5$3,037$3,634$6,670$46,849
6$3,272$3,398$6,670$43,577
7$3,526$3,145$6,670$40,051
8$3,799$2,871$6,670$36,252
9$4,094$2,577$6,670$32,158
10$4,411$2,259$6,670$27,747
110 of 15
Math verified by automated testsUpdated 2026-09-092 sources cited

How this is worked out

The formula

Amount financed = price − down payment + financed fees

Without a balloon:  PMT = P × i(1 + i)^n ÷ ((1 + i)^n − 1)
With a balloon B:   PMT = (P − B ÷ (1 + i)^n) × i(1 + i)^n ÷ ((1 + i)^n − 1)

i = annual rate ÷ 12, n = years × 12.
The balloon is the balance still owed after the final regular payment.

Open How it’s calculated above to see this worked through with your own numbers.

What you enter

Purchase price
A number.in dollars · 0 or more · defaults to 75000
Down payment
Marine lenders typically want 10–20% down, more on older hulls.in dollars · 0 or more · defaults to 15000
Interest rate
A number.a percentage · from 0 to 40 · defaults to 7.49
Term
Marine loans run far longer than car loans — 15 and 20 years are standard on larger boats.from 1 to 25 · whole numbers only · defaults to 15
Balloon payment
A lump due at the end. The payments only amortize the rest. 0 for a normal loan.a percentage · from 0 to 100 · defaults to 0
Fees rolled into the loan(under More options)
Documentation, registration, delivery and any sales or use tax you finance.in dollars · 0 or more · defaults to 0

What you get back

Monthly paymentmain answer
Amount financed
Balloon due at the end
Total interest
Total of payments plus balloon
Total cost of the boat
Down payment plus every payment plus the balloon.
Interest as a share of the loan
Interest in the first payment
Loan-to-value at purchase
Amount financed ÷ price. Above 100% means you start underwater.

What this assumes

  • Fixed rate, level monthly payments, simple interest on the declining balance.
  • The balloon is a percentage of the amount financed and falls due with the final payment.
  • Insurance, storage, maintenance and fuel are excluded — they typically exceed the loan payment.
  • Financed fees and taxes are added to the amount borrowed.

About this calculator

Boat loans look like car loans and behave like mortgages. Marine lenders write 15- and 20-year terms on larger boats, which keeps the payment down and stretches the interest out over a very long time on an asset that is losing value the entire way. That combination — long term, depreciating collateral — is the thing to understand before signing.

How to use it

Enter the price, your down payment, the quoted rate and the term. Roll registration, documentation, delivery and any financed sales or use tax into Fees under More options; they are part of what you borrow. If the lender is offering a balloon, enter it as a percentage of the loan: the payments then amortize only the rest, and the remainder comes due as a lump at the end.

What the long term really costs

At 7.5% on $60,000, a 15-year loan costs about $40,000 in interest — two-thirds of what you borrowed. The same loan over 10 years costs about $25,000, with a payment about $150 higher. Marine lenders lead with the payment for exactly this reason. Look at total interest and interest as a share of the loan before you decide the payment is affordable.

Balloons and being underwater

A balloon cuts the payment because you are only paying down part of the balance. The bill still arrives: at the end you must refinance the balloon, sell the boat for at least that much, or write a cheque. Boats depreciate roughly 20–30% in the first two years and keep going, so a boat that is 15 years old at balloon time is often worth less than the balloon. Being underwater matters the moment you want to sell — you have to bring cash to the closing to clear the lien.

Costs this calculator doesn't include

The loan is the smaller half of boat ownership. Budget separately for insurance (roughly 1–2% of hull value a year), slip or storage, winterization, bottom paint, engine service, fuel and registration. A common rule of thumb is 10% of the purchase price a year in running costs, which on a $75,000 boat is more than the loan payment.

One tax note worth knowing

If a boat has a berth, a galley and a head, the IRS treats it as a qualified second home, and the interest on a secured loan against it may be deductible under the same rules as a mortgage (Publication 936). Only one second home qualifies, the loan must be secured by the boat, and you must itemize — check with a tax professional before counting on it.

Frequently asked questions

How long are boat loans?

Longer than most people expect. Small boats are financed over 5–10 years; anything above roughly $50,000 is commonly written over 15 or 20. The long term is what makes the payment look manageable, and it is also what makes the interest large.

How much down payment do boat lenders require?

Usually 10–20%, and more for older boats, houseboats or anything unusual. A larger down payment also improves the rate, because marine collateral is harder to repossess and resell than a car.

Is boat loan interest tax deductible?

It can be. IRS Publication 936 treats a boat with sleeping, cooking and toilet facilities as a qualified second home, so interest on a loan secured by it may be deductible if you itemize and don't already claim another second home. Confirm with a tax professional.

What is a balloon payment on a boat loan?

A large lump sum due at the end of the term. The regular payments amortize only part of the balance, so the payment is lower, but you must refinance, sell, or pay the balloon when it comes due — and the boat may be worth less than the balloon by then.

Should I use a home equity loan instead?

Sometimes. Home equity rates can be lower and the interest may be deductible when the funds are used on the home, but the collateral is your house, not the boat. That is a real risk transfer, not a technicality.

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