Boat Loan Calculator

See the monthly payment and total cost of financing a boat over a longer marine-loan term.

How the Boat Loan Calculator works

The calculator amortizes the amount you finance over a long marine-loan term using the standard fixed-payment formula, then splits each payment into interest and principal. Boat loans use the same math as a mortgage or auto loan, but the long term (often 10 to 20 years) is what makes the interest stack up while the boat itself depreciates.

The formula is:

Monthly payment = P × [ i(1+i)ⁿ ] / [ (1+i)ⁿ − 1 ]

• P = principal, the amount financed after your down payment and any trade-in.
• i = the monthly rate, your annual APR divided by 12 (a 7.49% rate becomes 0.0749 / 12 = 0.0062417).
• n = total number of monthly payments (years × 12; a 15-year boat loan is 180 payments).

Internally the tool runs these steps:

1. You enter the amount financed directly, so P is your input — subtract your down payment and trade-in before entering it.
2. Convert the APR to a monthly rate i and the term to n months.
3. Solve the formula above for the level monthly payment.
4. Build a full amortization schedule: each month, interest = current balance × i, principal = payment − interest, and the balance drops by that principal.
5. Sum every payment to get total cost, then subtract P to get total interest.

Edge cases it handles: a 0% APR promo (it switches to P / n so it never divides by zero), marine terms as long as 20 years, and fractional rates like 6.99%. It does not bake in the marine survey fee, registration, sales tax, slip or storage, or the required marine insurance — those are real boat costs you pay outside the loan, so add them separately when you judge affordability. That gap between the financed amount and the true cost of ownership is bigger for a boat than for almost any other consumer loan.

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Example calculation

Here are three worked boat-financing scenarios, every figure recomputed from the formula above.

Example 1 — New cruiser, 15-year term. You finance $60,000 at 7.49% APR over 15 years. The monthly rate is 0.0062417 and n = 180. The payment works out to $555.87. Over 180 months you pay $100,055.97, so total interest is $40,055.97 — you pay two-thirds of the boat's price again, purely in interest, because the balance stretches across 15 seasons.

Example 2 — Same boat, 10-year term. Keep $60,000 at 7.49% but shorten to 10 years (n = 120). The payment rises to $711.90, but total interest drops to $25,427.70. Paying $156.03 more a month saves you $14,628.27 in interest — the clearest argument against stretching a marine term just to shrink the sticker payment.

Example 3 — Used boat, higher rate. A pre-owned boat financed at $35,000, 9.25% APR, 12 years (used boats carry higher rates and shorter maximum terms than new hulls). The payment is $403.25 and total interest is $23,068.68 — nearly two-thirds of the amount borrowed paid again in interest, driven by the steeper used-boat rate.

Scenario	Amount financed	Rate	Term	Monthly payment	Total interest	Total cost
New cruiser, long term	$60,000	7.49%	15 yr	$555.87	$40,055.97	$100,055.97
Same boat, shorter term	$60,000	7.49%	10 yr	$711.90	$25,427.70	$85,427.70
Used boat, higher rate	$35,000	9.25%	12 yr	$403.25	$23,068.68	$58,068.68

Notice the trap in Example 1: the low $555.87 payment feels affordable, but the 15-year term is what creates the $40,000 interest bill, and the boat will have depreciated hard long before the loan is paid. To pressure-test whether that monthly figure still fits once marine insurance and slip fees are added, run it through the loan affordability calculator too.

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Tips for using the Boat Loan Calculator

• Run the same amount at 10, 15, and 20 years before signing. On $60,000 at 7.49%, moving from 15 to 10 years adds $156 a month but saves $14,628 in interest; a 20-year term often saves only a little monthly over 15 while adding tens of thousands, because the marine rate compounds over twice as long.
• Budget for the marine survey up front. Lenders and insurers usually require an independent survey on used or higher-value boats, often $15 to $25 per foot (roughly $450 to $750 on a 30-footer), and you pay it out of pocket before the loan funds.
• Check whether your boat qualifies as a second home. If it has a sleeping berth, a galley (cooking) and a head (toilet), the loan interest may be deductible like a second-home mortgage if you itemize and have not already used the second-home deduction elsewhere.
• Add marine insurance, slip or dry storage, haul-out, and winterizing to the monthly payment, not on top of it as an afterthought. On a long term these off-season costs can rival the loan payment itself, so the payment alone badly understates true ownership cost.
• Put more down than the minimum to fight depreciation. Boats lose value fast in the early years, and a thin down payment plus a 20-year term can leave you underwater for years — the marine version of negative equity on a car.
• Ask the lender whether the rate is fixed for the full term. Some long marine loans carry a balloon or a rate reset; confirm the quoted payment really runs all 180 or 240 months and is not a teaser.
• Compare a marine loan against a home equity loan if you have equity. A secured home-equity rate can beat a boat rate, but you are then putting your house behind the boat, so weigh the risk before using the home-equity-loan-calculator.
• Get new-versus-used quotes in writing separately. The same dealer often offers a lower rate and a longer maximum term on a new hull than on the identical used model, because used boats are riskier, faster-depreciating collateral.
• Confirm there is no prepayment penalty. On a 15- or 20-year boat loan, paying even one extra payment a year shortens the term and cuts interest sharply, but only if the lender allows penalty-free prepayment.
• Finance the boat only, not the gear. Rolling a trailer, electronics, or a dinghy into a 15-year boat loan means paying 15 years of interest on items that wear out or depreciate far faster than the hull.

Boat loan vs auto loan vs RV loan: why the term changes everything

Boats are financed over far longer terms than cars and are used differently from RVs, which makes the interest math — not just the rate — the thing that costs you. An auto loan usually maxes out around 5 to 7 years; a boat or yacht loan can run 10 to 20 years on larger amounts. Stretching repayment over two decades keeps the monthly payment low but multiplies total interest, and a boat keeps depreciating while that long balance is still outstanding.

The use pattern differs from an RV too. An RV is more often lived in or used as a primary or near-primary residence for stretches, while a boat is typically recreational and seasonal — it may sit in storage half the year while you still pay the loan, the slip, and the marine insurance. Both a boat and an RV can qualify as a second home if they have sleeping, cooking and toilet facilities, but the carrying costs unique to a boat (marine survey, haul-out, winterizing, marine insurance with the lender as loss payee) set it apart.

Feature	Auto loan	RV loan	Boat loan
Typical term	3-7 years	10-20 years	10-20 years
Primary use	Daily transport	Travel / part-time residence	Recreational, seasonal
Special inspection	None typical	Sometimes	Marine survey often required
Second-home deduction	No	Possible	Possible (berth, galley, head)
Off-season carrying cost	Low	Moderate	High (slip, storage, winterize)

Compare side by side with the auto loan calculator and the RV loan calculator to see how the much longer marine term reshapes the same borrowed amount.

Common mistakes when financing a boat

The biggest mistake is judging the boat by its monthly payment instead of its total cost and true ownership expense. Here are the errors that cost boat buyers the most:

• Chasing the lowest payment with the longest term. A 20-year boat loan can look affordable monthly while quietly adding tens of thousands in interest, as the worked examples above show.
• Forgetting the survey and closing costs. The marine survey, documentation, and registration are paid outside the loan and surprise first-time buyers who only budgeted the down payment.
• Ignoring off-season costs. Slip or dry storage, haul-out, winterizing, and required marine insurance continue every month the boat sits unused through the off-season.
• Assuming the interest is automatically deductible. It only helps if you itemize, the boat has berth, galley and head, the loan is secured by the boat, and you have not already claimed a second home elsewhere.
• Underestimating depreciation. A small down payment plus a long term leaves you owing more than the boat is worth for years — the marine version of being underwater on a car loan.
• Rolling gear and extras into the boat loan. Financing electronics, a trailer, or a dinghy over 15 years means paying interest long after they are worn out.

How to calculate a boat payment by hand or in Excel

You can reproduce this calculator in any spreadsheet with one PMT function. Open Excel or Google Sheets and use:

=PMT(rate/12, years*12, -principal)

For the new-cruiser example ($60,000 at 7.49% over 15 years), that is =PMT(0.0749/12, 15*12, -60000), which returns $555.87. The principal is entered as a negative because it is money you receive; the result then comes back positive.

To see total interest, multiply the payment by the number of months and subtract the principal: =PMT(0.0749/12,180,-60000)*180-60000 gives $40,055.97. To check how much of the very first payment is interest, use =60000*0.0749/12, which is $374.50 — meaning only $181.37 of that first $555.87 actually pays down the boat, and the rest is interest on a hull that is already losing value. By hand, the formula is Payment = P × i(1+i)ⁿ / ((1+i)ⁿ − 1), with i = 0.0749/12 and n = 180. The same approach works for any fixed loan; the generic loan calculator uses identical math.

Is your boat loan rate and term good? Benchmarks to check against

A good boat loan keeps the term as short as the payment allows and the rate competitive for the boat's age and your credit. Use these reference points rather than a single headline number, because marine rates move with the market and your profile:

• New vs used spread: Used boats commonly carry a higher rate and a shorter maximum term than new ones — expect a meaningful gap, not a token one, because older hulls are riskier collateral.
• Down payment: Many marine lenders look for roughly 10% to 20% down. On a $75,000 boat, 20% down ($15,000) finances $60,000; 10% down finances $67,500, which raised the 15-year payment from $555.87 to $625.35 in our math and added about $5,000 in interest.
• Term discipline: If you can carry the payment at 10 or 12 years instead of 20, do it — the interest difference is usually larger than buyers expect.
• Total interest sanity check: If projected interest approaches half or more of the amount financed, the term is probably too long or the rate too high for the boat's age.

Before committing, confirm the payment fits your real budget with the debt-to-income ratio calculator so the boat does not crowd out your other obligations.

Can a boat be a second home for the mortgage-interest deduction?

Yes — a boat with sleeping, cooking and toilet facilities can be treated as a qualified second home, so the loan interest may be deductible if you itemize. Under the IRS rules for home mortgage interest, a residence must have a sleeping space (berth), cooking facilities (galley) and a toilet (head). A boat meeting all three can qualify as your one second home for this deduction.

Important limits apply: the loan must be secured by the boat itself, you can designate only one second home at a time, you must itemize rather than take the standard deduction, and the overall mortgage-interest debt limits still apply. A day boat or open runabout with no head or galley does not qualify. Tax rules change, so confirm current eligibility and dollar limits with the IRS or a tax professional before counting on the write-off. In the new-cruiser example, first-year interest is roughly $4,417.71; for a buyer who itemizes in a 22% bracket, that interest could translate to around $972 of tax saving — helpful, but never a reason to buy more boat than you need.

Secured collateral, the marine survey, and required insurance

A boat loan is secured by the boat itself, which is why lenders require both a marine survey and continuous marine insurance. The survey is an independent inspection of the hull, engine, systems and value — it protects the lender's collateral and is usually required for used boats and most higher-value purchases. You pay for it before the loan closes (commonly $15 to $25 per foot, so roughly $450 to $750 on a 30-foot boat), and a poor survey can lower the amount a lender will advance or kill the deal entirely.

Because the boat backs the loan, lenders also require you to keep marine insurance for the full term, listing the lender as a loss payee. That premium is separate from your monthly payment and continues every month, including the off-season when the boat never leaves the dock. If you let coverage lapse, the lender can force-place expensive insurance or call the loan. Factor both the one-time survey and the ongoing insurance into your decision — they are real costs that the payment figure alone, and a generic loan tool, will never show you.

Advanced uses: down payment, refinancing, and total cost of ownership

The smartest way to use this calculator is to model the whole ownership picture, not just the loan in isolation. Try these:

• Size your down payment. Re-run the amount financed at 10% and 20% down to see both the payment and the interest swing — on a $75,000 boat that is the difference between financing $67,500 and $60,000 — then decide with the down payment calculator.
• Test a refinance. If marine rates fall or your credit improves, enter the remaining balance, the new rate and the remaining term to compare against your current payment.
• Build a true monthly cost. Add marine insurance, slip or storage, fuel, and maintenance to the calculated payment so you are budgeting for ownership, not just borrowing.
• Compare against paying cash. If you would otherwise invest that money, weigh the loan's interest cost against potential returns before financing a depreciating asset.

Because a boat is seasonal, also remember you carry insurance and storage in the months the boat never leaves the dock — a cost that auto and most everyday loans simply do not impose.

Boat loan quick reference: monthly payment and total interest by rate and term

A boat financed over a longer term has a lower monthly payment but a much higher total interest cost, and used boats usually carry higher rates and shorter terms than new boats. The table below shows a $75,000 amount financed at two representative rates across 10-, 15-, and 20-year terms. Every figure is recomputed from the standard amortized-loan formula; your actual rate depends on credit, boat age, the marine survey, and down payment. Marine insurance, storage, and survey fees are additional and not shown here.

Rate	Term	Monthly payment	Total interest	Total cost
6.5%	10 years	$851.61	$27,193.18	$102,193.18
6.5%	15 years	$653.33	$42,599.49	$117,599.49
6.5%	20 years	$559.18	$59,203.16	$134,203.16
8.5%	10 years	$929.89	$36,587.12	$111,587.12
8.5%	15 years	$738.55	$57,939.84	$132,939.84
8.5%	20 years	$650.87	$81,208.18	$156,208.18

Reading down each rate, doubling the term from 10 to 20 years cuts the payment by roughly a third but more than doubles total interest — at 8.5%, interest jumps from $36,587 to $81,208. Use this boat loan calculator to test your own amount, rate, and term.

Related on this site

General Loan Calculator · Auto Loan Calculator · RV Loan Calculator · Home Equity Loan Calculator · Down Payment Calculator · Loan Affordability Calculator

For a related deep dive, see IRS Pub 936 (second-home mortgage interest).

Boat Loan Calculator — frequently asked questions

Why are boat terms long?

Boats are financed over 10–20 years to keep payments low, which raises total interest.

Is insurance required?

Lenders usually require marine insurance, billed separately from the loan.

Can I deduct boat loan interest?

If the boat has sleeping, cooking and toilet facilities it may qualify as a second home — check current tax rules.

New vs used boat rates?

Used boats typically carry higher rates and shorter maximum terms.

How much does a $60,000 boat loan cost per month at 7.5% over 15 years?

A $60,000 boat loan at 7.5% over 15 years runs about $556 a month. Stretching to 15 years keeps the payment low, but you repay roughly $40,117 in interest on top of the $60,000 borrowed, for a total of about $100,117. The same $60,000 at 7.5% over 7 years jumps to about $920 a month yet costs only about $17,305 in interest. Run your own numbers in the <a href="/boat-loan-calculator/">boat loan calculator</a>.

Is a 20-year boat loan worth it compared with a 10-year term?

A 20-year boat loan is rarely worth it unless the lower payment is the only way you can afford the boat. On $80,000 at 7.25%, a 10-year term costs about $939 a month and $32,705 in interest, while 20 years drops the payment to about $632 but balloons interest to about $71,752 - roughly $39,047 more. You pay nearly an extra full boat in interest to save about $307 a month.

How much can I save on a boat loan with 20% down instead of 10%?

Putting 20% down instead of 10% on a $60,000 boat can save you over $5,000 in interest and often earns a better rate. Financing $54,000 (10% down) near 8.49% over 12 years costs about $599 a month and $32,275 in interest. Financing $48,000 (20% down) near 7.99% costs about $519 a month and $26,781 in interest - about $80 less monthly and $5,493 less interest, plus less risk of going underwater as the boat depreciates.

What is the monthly payment on a $100,000 yacht loan at 6.99% over 20 years?

A $100,000 yacht loan at 6.99% over 20 years is about $775 a month. The long term keeps the payment manageable, but total interest reaches about $85,928 - roughly 86% of what you borrowed - for a total cost near $185,928. Cutting the term to 12 years raises the payment to about $1,028 but slashes interest to about $48,010. Larger marine loans almost always favor a shorter term.

Can a boat really qualify as a second home for the mortgage interest deduction?

Yes - a boat can qualify as a second home if it has sleeping, cooking, and toilet facilities (a berth, a galley, and a head). When it qualifies and the loan is secured by the boat, the interest may be deductible like a second-home mortgage, subject to current IRS limits. On a $90,000 loan at 7% over 15 years, first-year interest is about $6,189, worth roughly $1,361 in the 22% bracket. Confirm current rules with a tax professional.

How much boat loan interest can I deduct on a $60,000 loan in the first year?

On a $60,000 boat loan at 7.5% over 15 years, first-year interest is about $4,424, so a 22% bracket would save roughly $973 if the boat qualifies as a second home. The boat must have sleeping, cooking, and toilet facilities, the loan must be secured by the boat, and you cannot already be deducting two qualified homes. Deductible interest shrinks each year as the balance falls. Verify eligibility with a tax advisor.

How do I calculate a boat loan payment in Excel?

Use Excel's PMT function: =PMT(rate/12, years*12, -amount). For a $45,000 boat at 8% over 10 years, enter =PMT(0.08/12, 120, -45000), which returns about $545.97 a month. Keep the loan amount negative so the result shows as a positive payment. Multiply the payment by the number of months and subtract the amount borrowed to find total interest - about $20,517 here. The <a href="/boat-loan-calculator/">boat loan calculator</a> does this instantly.

Why are used boat loan rates higher and terms shorter than new boats?

Used boat loans carry higher rates and shorter maximum terms because older boats depreciate fast and are riskier collateral. A $30,000 used boat at 9.49% over 10 years runs about $388 a month and $16,563 in interest, while a comparable new-boat rate near 6.49% would cost noticeably less. Many lenders also cap term length by boat age, so a 20-year-old hull may only get a 7-to-10-year loan even when newer boats qualify for 15 to 20 years.

How is a boat loan different from an RV loan?

A boat loan and an RV loan look similar but differ in use and risk. RVs are more often used as primary or full-time residences and can be titled accordingly, while boats are typically recreational and seasonal. Boats also need a marine survey, marine insurance with the lender as loss payee, and off-season storage, and they tend to depreciate faster. Both can qualify as a second home with sleeping, cooking, and toilet facilities. Compare with the <a href="/rv-loan-calculator/">RV loan calculator</a>.

Why are boat loan terms so much longer than car loan terms?

Boat loan terms run 10 to 20 years versus about 5 to 7 for most car loans because boats cost more and lenders stretch payments to keep them affordable. The trade-off is far more interest. A $45,000 boat at 8% over 5 years costs about $912 a month but only $9,746 in interest; over 20 years the payment drops to about $376 while interest climbs to about $45,336 - more than four times as much. Longer is cheaper monthly, costlier overall.

Will I go underwater on my boat loan because of depreciation?

You can easily go underwater because boats depreciate faster than the loan balance falls on long terms. Finance $50,000 at 8% over 15 years with a small down payment, and after 3 years you still owe about $44,143 - yet a new boat that lost 25% of its value would be worth about $37,500. That roughly $6,600 gap means you owe more than the boat is worth. A larger down payment and a shorter term protect against negative equity.

Is 10.5% a good interest rate on a boat loan?

A 10.5% boat loan rate is on the high side and usually signals an older or used boat, a smaller loan, or weaker credit. On a $25,000 boat at 10.5% over 8 years, you would pay about $386 a month and $12,056 in interest. Strong credit on a newer boat can land rates several points lower, which on the same loan could save thousands. Shop multiple marine lenders and credit unions before accepting double-digit rates.

What does a marine survey cost and is it required for a boat loan?

A marine survey is usually required by lenders and insurers for used boats and larger vessels, and it commonly runs about $15 to $25 per foot - roughly $450 to $750 for a 30-foot boat. The survey verifies the boat's condition and value, which protects the lender's collateral. Budget it as an upfront closing cost on top of your down payment, and remember marine insurance is also typically mandatory and billed separately from the loan.

How much do seasonal storage and insurance add on top of a boat loan payment?

Storage, winterization, and required marine insurance can add hundreds of dollars a month on top of the loan payment, so the true cost is well above the financing alone. On a $50,000 boat at 7.99% over 10 years, the loan is about $606 a month and $22,765 in interest - but off-season storage, haul-out, and insurance premiums are separate and ongoing. Add these recurring costs to your budget before deciding how much boat you can truly afford.

How much more interest does a 10% rate cost than 6% on a $50,000 boat over 15 years?

A 10% rate costs about $20,767 more interest than 6% on a $50,000 boat over 15 years. At 6% the payment is about $422 a month and interest totals about $25,947; at 8% it is about $478 and $36,009; at 10% it climbs to about $537 a month and $46,714 in interest. Every two points of rate adds roughly $10,000 in interest over the term, which is why a strong credit profile and a marine survey that supports value matter so much.

Guides & articles

• Why Boat Loans Have Such Long Terms - and What It Really Costs
• The True Cost of Owning a Boat - Beyond the Monthly Payment

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