An auto loan calculator estimates your monthly payment and total interest from the vehicle price, tax rate, fees, down payment, trade-in, APR, and term. This tool applies the entered tax rate to the full vehicle price, adds fees, then subtracts the down payment and trade-in. It does not determine local tax treatment or include unentered add-ons.
Look beyond the monthly payment: the amount financed, APR, term, and total interest all affect what you pay. A longer term can lower the scheduled payment while increasing the total interest in the calculator's estimate.
Compare written offers using the same loan amount and term, and review the APR and total of payments as well as the monthly amount. The CFPB explains how APR and interest rates differ in its auto-loan borrowing-cost guide.
How to Use the Auto Loan Calculator
- Start with the price: Enter the Vehicle Price before tax and before any trade-in, then add your Down Payment and Trade-In Value, leaving those at zero if they do not apply.
- Add tax and fees: Enter the Sales Tax percentage and any Dealer & Document Fees; both are financed with the car in this estimate.
- Set the rate: Type the APR the lender offered and choose the Currency.
- Pick a term: Choose the Loan Term from 24 to 84 months, keeping in mind that a longer term lowers the payment and raises the total interest.
- Calculate: Click Calculate to see the Monthly Payment, Out the Door (Price + Tax + Fees), Amount Financed, Total Interest, and Total Cost With Upfront Money.
View Payment Schedule lays out each month's principal and interest, and the breakdown bar shows what share of your payments goes to the lender rather than the car.
Beyond the Sticker Price: What Determines Your Car Payment
For this tool, the estimate is: Amount financed = vehicle price + entered tax + entered fees − cash down payment − trade-in credit. The payment is then calculated over the selected term using the APR you enter. Use the offer's APR and actual line-item costs for a closer estimate.
Vehicle Purchase Price, Rebates, and Cash Down Payment
Enter the vehicle price you expect to pay. If a rebate changes the agreed selling price, reflect that in the price you enter; this calculator has no separate rebate field.
Extra cash down works directly in the model. On the example below, adding $1,000 to the down payment cuts the amount financed from $29,950 to $28,950, and at 6.50% APR over 60 months the payment falls from $586.01 to $566.44 — about $19.57 a month — while modeled interest drops from $5,210.37 to $5,036.39, a saving of $173.98 over the term.
How entered taxes and dealer fees affect the estimate
Enter the applicable tax percentage and any fees you want included. Actual tax bases and rates can vary by location and transaction; this tool simply applies the percentage you enter to the vehicle price. Its fee field is a single amount for dealer or document fees and does not look up local charges.
Factoring in Your Trade-In Vehicle
Trading in an existing vehicle can significantly alter your financing package, but its financial impact depends entirely on your current vehicle equity.
Applying Positive Trade-In Equity as Down Payment
The calculator subtracts the trade-in credit you enter from the new vehicle's price, but it has no field for a payoff on an existing vehicle loan. Two caveats determine how close the estimate is to your deal:
- Net the payoff yourself: If the old loan is paid from the trade-in proceeds, account for that payoff when determining the credit you enter; for example, a $12,000 allowance minus a $9,000 payoff leaves $3,000 in positive equity. The example table assumes the entered $3,000 is already net of any payoff.
- Tax treatment varies: Some jurisdictions adjust the taxable purchase price for a trade-in, while others use different rules. This calculator does not reduce its tax estimate by the trade-in amount, so check the tax treatment on your buyer's order or with the relevant tax authority.
Handling Negative Equity ("Underwater" Vehicle Rollovers)
Negative equity occurs when you owe more on your current vehicle loan than the car is worth: commonly referred to as being "underwater" or "upside-down." If your loan payoff is $15,000 but the vehicle is valued at $11,000, you have $4,000 in negative equity.
This calculator does not accept a negative trade-in value or an old-loan payoff, so it cannot model negative equity directly. Review the new contract's amount financed to see whether any unpaid balance has been included.
Calculating the Complete Vehicle Financing Cost
Evaluating an auto loan requires examining both the monthly installment and the cumulative financing cost over the full loan term.
Total Financed Principal vs Total Interest Paid
Every dollar borrowed incurs interest calculated on a declining principal balance. The table below shows the payment breakdown for a $35,000 vehicle with $5,000 down, $3,000 trade-in credit, 7% sales tax ($2,450), and $500 in dealer fees, resulting in a net financed principal of $29,950 at 6.50% APR:
| Financing Metric | 36 Months (3 Yrs) | 48 Months (4 Yrs) | 60 Months (5 Yrs) | 72 Months (6 Yrs) | 84 Months (7 Yrs) |
|---|---|---|---|---|---|
| Vehicle Out-the-Door Price | $37,950.00 | $37,950.00 | $37,950.00 | $37,950.00 | $37,950.00 |
| Upfront Contribution (Down + Trade-In Credit) | $8,000.00 | $8,000.00 | $8,000.00 | $8,000.00 | $8,000.00 |
| Net Amount Financed | $29,950.00 | $29,950.00 | $29,950.00 | $29,950.00 | $29,950.00 |
| Monthly Payment | $917.94 | $710.27 | $586.01 | $503.46 | $444.75 |
| Total Interest Accrued | $3,095.72 | $4,142.57 | $5,210.37 | $6,298.90 | $7,407.95 |
| Total Amount Repaid to Bank | $33,045.72 | $34,092.57 | $35,160.37 | $36,248.90 | $37,357.95 |
| Total Cost (Down + Trade-In Credit + Loan Payments) | $41,045.72 | $42,092.57 | $43,160.37 | $44,248.90 | $45,357.95 |
The Monthly Payment Formula for Auto Financing
For a fixed monthly payment, the calculator uses the standard installment-loan formula:
M = P * [ r(1 + r)^n ] / [ (1 + r)^n - 1 ]
Where:
- M: Fixed monthly car payment.
- P: Net amount financed (out-the-door vehicle price minus down payment and trade-in).
- r: Monthly periodic interest rate (annual APR divided by 12).
- n: Total term duration in months (e.g., 36, 48, 60, 72, or 84).
How Loan Term Changes Payment and Total Interest
The calculator offers terms of 24, 36, 48, 60, 72, and 84 months. A longer term generally lowers the modeled monthly payment while giving interest more time to accrue; compare both the payment and total interest.
Lower Payments vs Long Terms and Depreciation Risk
A vehicle's resale value can fall faster or slower than the loan balance, depending on the vehicle, market, mileage, down payment, APR, and term. A longer loan can leave less room to absorb depreciation, so compare the amount financed with your expected ownership plans rather than choosing by payment alone.
As demonstrated in our comparison table, extending the term on a $29,950 loan from 48 to 84 months reduces the monthly payment by $265.52, but increases total interest charges by $3,265.38 (a 79% surge in financing costs).
Understanding a Possible Insurance Gap
If an insured vehicle is declared a total loss, the insurer's settlement and the loan payoff may not match. The difference depends on policy terms, vehicle value, and the outstanding balance.
Guaranteed asset protection (GAP) products may cover some of this difference, subject to the contract's coverage, exclusions, cost, and eligibility. Consider the written terms and your circumstances; this calculator does not determine whether GAP coverage is suitable or include its cost.
Credit Tier Realities in Auto Lending
The rate available to you depends on the lender, offer, vehicle, loan term, and borrower qualifications. For orientation only, rate sheets are commonly grouped into tiers along these lines:
| Commonly Cited Tier | Illustrative APR Band |
|---|---|
| Super-prime (strongest credit histories) | ~5%–6% |
| Prime | ~6%–9% |
| Non-prime | ~9%–15% |
| Subprime | ~15%–20% |
| Deep subprime | ~20% and above |
Illustrative, commonly cited ranges — not current market data; verify with your own offer.
Compare Written Offers, Not Credit-Tier Averages
Rates and eligibility can vary between lenders and offers, and credit-score labels do not guarantee a particular APR. Compare the APR, amount financed, term, required fees, and total of payments in the offers you actually receive.
Dealer Markup on Financing ("Buy Rate" vs "Contract Rate")
When financing through a dealer, ask which lender is providing the loan and review the APR, term, and total payment obligation in the contract. You can also compare the dealer's written offer with a separate lender preapproval; an outside offer does not require the dealer to match it.
To establish a sound vehicle budget before shopping, explore our Car Affordability Calculator, determine the fastest path to eliminating your existing car debt with our Car Loan Payoff Calculator, or verify your effective annual financing percentage using our APR Calculator. If rates have fallen or your credit has improved, test a replacement loan with the Auto Loan Refinance Calculator; for a two-wheeler purchase, use the Motorcycle Loan Calculator.
Terms in this calculator run to 84 months, and a 96-month term is outside the range it will price. The estimate assumes the schedule runs as agreed, so it does not model extra payments for an early payoff; to price a payoff from the current balance instead, use the Car Loan Payoff Calculator.
Last verified: October 2026. Calculator figures are outputs for the inputs entered; they are not live quotes, current rates, or an offer.