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ToolNest
Finance & Tax

Auto Loan Calculator

Work out your real car payment — including trade-in equity, negative equity, sales tax and dealer fees — then compare every loan term side by side. Built on the official CFPB amortisation formula.

Your auto loan

$32,000
$8,000

$5,000 equity toward the deal

$4,000
7.9%
Loan term
Months
Monthly payment
$515

7.90% over 5 yrs

Amount financed
$25,460

$4,000 down · $5,000 trade equity

Total interest
$5,441
Total cost of the car
$30,901

Financed amount + interest

Total car cost breakdown

Where every dollar of the deal goes: principal, interest, sales tax and dealer fees.

Total car cost breakdownWhere every dollar of the deal goes: principal, interest, sales tax and dealer fees.
$33,361all-in cost
  • Principal financed
  • Interest
  • Sales tax
  • Dealer fees
Total car cost breakdown
CategoryValue
Principal financed$25,460
Interest$5,441
Sales tax$1,560
Dealer fees$900

What you actually pay for

Cash down plus trade equity versus the amount you borrow.

What you actually pay forCash down plus trade equity versus the amount you borrow.
$32,000vehicle price
  • Cash down
  • Trade-in equity
  • Financed
What you actually pay for
CategoryValue
Cash down$4,000
Trade-in equity$5,000
Financed$25,460

Loan payoff curve

The outstanding balance falls fastest in the final years as interest gives way to principal.

Loan payoff curveThe outstanding balance falls fastest in the final years as interest gives way to principal.$0$5,284$10,568$15,853$21,137Y1Y2Y3Y4Y5
  • Remaining balance
  • Cumulative interest
Loan payoff curve
CategoryValue
Y1Remaining balance: $21,137 · Cumulative interest: $1,857
Y2Remaining balance: $16,459 · Cumulative interest: $3,360
Y3Remaining balance: $11,399 · Cumulative interest: $4,480
Y4Remaining balance: $5,924 · Cumulative interest: $5,185
Y5Remaining balance: $0 · Cumulative interest: $5,441

Term comparison — monthly payment

A longer term lowers the monthly payment but raises the total interest you pay.

Term comparison — monthly paymentA longer term lowers the monthly payment but raises the total interest you pay.$79736m$62048m$51560m$44572m$39684m
  • 36m
  • 48m
  • 60m
  • 72m
  • 84m
Term comparison — monthly payment
CategoryValue
36m$797
48m$620
60m$515
72m$445
84m$396

Term comparison — total interest

The same loan priced across every term a dealer typically offers.

Term comparison — total interestThe same loan priced across every term a dealer typically offers.36 months$3,21948 months$4,31760 months$5,44172 months$6,59184 months$7,767
  • 36 months
  • 48 months
  • 60 months
  • 72 months
  • 84 months
Term comparison — total interest
CategoryValue
36 months$3,219
48 months$4,317
60 months$5,441
72 months$6,591
84 months$7,767

Amortization schedule

60 payments · 60 rows

#InterestPrincipalExtraBalance
1$168$347—$25,113
2$165$350—$24,763
3$163$352—$24,411
4$161$354—$24,057
5$158$357—$23,700
6$156$359—$23,341
7$154$361—$22,980
8$151$364—$22,616
9$149$366—$22,250
10$146$369—$21,881
11$144$371—$21,510
12$142$373—$21,137
13$139$376—$20,761
14$137$378—$20,383
15$134$381—$20,002
16$132$383—$19,618
17$129$386—$19,233
18$127$388—$18,844
19$124$391—$18,453
20$121$394—$18,060
21$119$396—$17,663
22$116$399—$17,265
23$114$401—$16,863
24$111$404—$16,459
25$108$407—$16,053
26$106$409—$15,643
27$103$412—$15,231
28$100$415—$14,817
29$98$417—$14,399
30$95$420—$13,979
31$92$423—$13,556
32$89$426—$13,130
33$86$429—$12,702
34$84$431—$12,270
35$81$434—$11,836
36$78$437—$11,399
37$75$440—$10,959
38$72$443—$10,516
39$69$446—$10,070
40$66$449—$9,621
41$63$452—$9,170
42$60$455—$8,715
43$57$458—$8,257
44$54$461—$7,797
45$51$464—$7,333
46$48$467—$6,866
47$45$470—$6,397
48$42$473—$5,924
49$39$476—$5,448
50$36$479—$4,968
51$33$482—$4,486
52$30$485—$4,001
53$26$489—$3,512
54$23$492—$3,020
55$20$495—$2,525
56$17$498—$2,027
57$13$502—$1,525
58$10$505—$1,020
59$7$508—$512
60$3$512—$0

Figures are estimates for planning only. They exclude optional extended warranties, gap insurance, negative-equity carry-over interest and any lender documentation fees not entered above. Your dealer's finance office is the authoritative source for the final contract.

The formula behind your car payment

Auto loans are amortising loans, repaid with the same equation that governs mortgages and personal loans. In the United States it is standardised by the Consumer Financial Protection Bureau in Regulation Z, Appendix J:

M = P × [ i(1 + i)^n ] ÷ [ (1 + i)^n − 1 ]
  • M — the monthly payment
  • P — the amount financed (not the sticker price)
  • i — the monthly interest rate (APR ÷ 12)
  • n — the total number of monthly payments

The amount financed is the figure that matters, and it is built up in a specific order:

P = Price + Sales tax + Dealer fees − Trade-in equity − Cash down

Trade-in equity is the trade-in value minus whatever you still owe on it. If that number is negative you have negative equity, and the shortfall is added to the new loan rather than subtracted. Sales tax is charged on the price minus the trade-in value in the roughly 40 states that grant a trade-in tax credit. The remaining balance after any payment follows Freddie Mac's Form 91 closed form: Bₖ = P(1 + i)ᵏ − M × [ ((1 + i)ᵏ − 1) ÷ i ].

Worked examples

United States — 60-month dealer financing

A $32,000 vehicle with an $8,000 trade-in on which $3,000 is still owed gives $5,000 of trade equity. Sales tax at 6.5% applies to the $24,000 difference, adding $1,560. Add $900 in dealer and registration fees and subtract a $4,000 cash down payment, and the amount financed is $25,460. At 7.9% over 60 months the payment is $515.02 and total interest is $5,441.16 — an all-in cost of about $33,361.

United Kingdom — hire purchase (HP)

UK car finance is quoted with a flat or APR-based rate. A £20,000 vehicle with a £3,000 deposit leaves £17,000 financed. At 8.9% APR over 48 months the payment is about £422 per month. UK agreements must disclose the total amount payable under FCA CONC rules, which for this example is roughly £20,267. VAT is normally already included in the quoted price, so set the sales tax slider to 0.

Eurozone — consumer credit

In the euro area the same annuity formula applies, and lenders must disclose the effective annual rate (APR) under the Consumer Credit Directive 2008/48/EC. A €25,000 vehicle with a €5,000 deposit leaves €20,000 financed. At 5.5% over 60 months the payment is about €382. VAT is included in the list price, so leave the sales tax slider at 0 and enter the on-the-road price directly.

How to use this calculator

  1. Enter the vehicle price the dealer has quoted you.
  2. Add your trade-in value and, in the advanced panel, the amount you still owe on it.
  3. Enter your cash down payment and the APR you have been offered.
  4. Choose a 36, 48, 60, 72 or 84-month term and compare the payment and total interest charts.
  5. Open the advanced panel to set your state sales tax rate and dealer fees for a true amount financed.
  6. Download the amortization schedule as CSV or share your exact scenario with a link.
FAQ

Frequently asked questions

Still unsure about something? Our contact page reaches a real person, usually within two business days.

How is a monthly car payment calculated?
Auto loans use the same amortising formula as mortgages, standardised in Regulation Z Appendix J: M = P × [ i(1 + i)^n ] ÷ [ (1 + i)^n − 1 ], where P is the amount financed, i is the monthly rate (APR ÷ 12) and n is the number of monthly payments. The amount financed is not the sticker price — it is the price plus sales tax and dealer fees, minus your trade-in equity and cash down payment.
Does a trade-in reduce the sales tax I pay?
In most US states, yes. Roughly 40 states plus the District of Columbia allow a trade-in tax credit, meaning sales tax is charged only on the difference between the new vehicle price and your trade-in value. A handful of states — including California, Hawaii, Kentucky and Michigan — charge tax on the full price with no trade-in credit. This calculator applies the credit by default; set the sales tax slider to 0 if your state does not allow it.
What is negative equity and how does it affect my loan?
Negative equity happens when you owe more on your trade-in than it is worth. That shortfall does not disappear — the dealer pays off your old lender and rolls the difference into the new loan, so you finance the new car plus the old debt. Enter the amount still owed in the advanced panel and the calculator will add it to the amount financed, raising both your payment and your total interest.
Should I choose a 60-month or 84-month car loan?
A longer term lowers the monthly payment but costs far more in interest and leaves you underwater on the car for longer. On a $25,460 loan at 7.9%, a 60-month term costs about $5,441 in interest while an 84-month term costs roughly $7,767 — over $2,300 more for the same car. The term-comparison charts above price every option side by side so you can see the trade-off in cash flow versus lifetime cost.
What fees should be included in the amount financed?
Include documentation fees, title and registration fees, and any dealer-installed accessories you are financing. Exclude optional add-ons you can decline — extended warranties, gap insurance, paint protection and credit insurance. Under the CFPB's auto-lending guidance these must be presented as optional, and financing them over 72 months can add hundreds of dollars in interest for a product you may never use.
How can I lower my car payment?
There are four levers: increase your down payment, improve your credit score to qualify for a lower APR, negotiate the vehicle price itself, and shorten the term. Paying an extra amount each month also helps — every extra dollar goes straight to principal, which is why the extra-payment slider above shows both the months saved and the interest saved. Refinancing after 12–18 months of on-time payments is another common route to a lower rate.