Auto Loan Calculator
Use this free auto loan calculator to find your exact monthly car payment on a new or used vehicle. Enter the vehicle price, down payment, trade-in value, sales tax rate, loan term, and interest rate (APR) to see your monthly payment, the total interest you'll pay, and a full year-by-year amortization schedule. Add an extra monthly payment to see how much faster — and cheaper — you can pay off your car loan.
What Is an Auto Loan Calculator?
An auto loan calculator is a tool that estimates your monthly car payment based on the vehicle's price, your down payment, any trade-in value, sales tax, the loan term, and the interest rate (APR) your lender offers. Instead of guessing what a car will cost you each month, you can model different price points, down payments, and loan terms before you ever step into a dealership or submit a loan application. This calculator also produces a full year-by-year amortization schedule so you can see exactly how much of every payment goes toward interest versus paying down the loan itself.
How Auto Loan Payments Are Calculated
Car loans are amortized loans: you repay a fixed amount every month until the balance reaches zero, with each payment split between principal and interest. Your monthly payment is calculated using the standard loan amortization formula:
M = P × [r(1+r)n] ÷ [(1+r)n − 1]
Where M is your monthly payment, P is the amount financed (not the sticker price — see below), r is your periodic interest rate, and n is the total number of monthly payments. In the early months of an auto loan, a larger share of each payment goes toward interest; as the balance shrinks, more of each payment chips away at the principal.
What Goes Into Your Total Auto Loan Cost
The amount you actually finance is rarely the same as the sticker price. It's calculated as:
Amount Financed = Vehicle Price + Sales Tax − Down Payment − Trade-In Value
- Vehicle price — the negotiated purchase price of the new or used car, before tax and fees.
- Sales tax — charged by most states on the purchase price; many states apply a trade-in tax credit, so tax is owed only on the price minus your trade-in value.
- Down payment — cash you pay upfront, directly reducing the amount financed and your monthly payment.
- Trade-in value — the appraised value of a vehicle you trade in, credited against the purchase price.
- Title, registration & documentation fees — smaller fixed fees that vary by state and dealer; add these to your vehicle price above if you want them reflected in your loan amount.
New Car Loans vs. Used Car Loans
| New Car Loan | Used Car Loan | |
|---|---|---|
| Typical interest rate | Lower | Higher |
| Typical maximum term | Up to 72-84 months | Usually 60-72 months |
| Depreciation risk | Highest in year one | Slower, more predictable |
| Manufacturer incentives | Often available (rebates, 0% APR promos) | Rarely available |
| Inspection/warranty risk | Covered by factory warranty | Varies — inspect before financing |
Lenders view new vehicles as lower-risk collateral because they depreciate more predictably and have full manufacturer warranties, which is why new-car APRs are consistently lower than used-car APRs for the same borrower.
Dealer Financing vs. Bank & Credit Union Auto Loans
| Loan Type | How It Works | Best For |
|---|---|---|
| Dealer / captive finance | Arranged at the dealership, often through the manufacturer's finance arm | Chasing 0% or subsidized promotional APRs on new cars |
| Bank or credit union | Pre-approved before you shop, funds paid directly to the seller | Negotiating leverage and predictable, often lower rates |
| Online / fintech lender | Fully digital application and approval, funds sent to seller or you | Fast pre-qualification and rate comparison across multiple lenders |
How Your Credit Score Affects Your Auto Loan Rate
Your credit score is the single biggest driver of the APR a lender will offer. The table below shows typical auto loan rate tiers — actual offers vary by lender, loan term, and whether the vehicle is new or used.
| Credit Tier | FICO Score Range | Typical New-Car APR | Typical Used-Car APR |
|---|---|---|---|
| Superprime | 720+ | Lowest available rates | Low rates |
| Prime | 660-719 | Competitive, near-average rates | Slightly above new-car average |
| Nonprime | 620-659 | Above-average rates | Noticeably higher rates |
| Subprime | 580-619 | High rates | Highest rate tier |
| Deep subprime | Below 580 | Very high rates, may need a co-signer | Very high rates, may need a co-signer |
Tiers are illustrative and for general guidance only — check current rates with individual lenders and your own credit report before applying.
Down Payment: How Much Should You Put Down on a Car?
A common rule of thumb is to put down at least 20% on a new car and 10% on a used car. A larger down payment shrinks your amount financed, lowers your monthly payment, reduces total interest, and helps you stay "right-side up" — meaning you owe less than the car is worth — even as it depreciates in the first year. If you can't reach that benchmark, prioritize a payment large enough to avoid rolling negative equity from a previous loan into the new one.
Trade-In Value: How It Lowers Your Loan Amount
Trading in your current vehicle works like an additional down payment: its appraised value is subtracted from the price of the new car before your loan amount — and in most states, your taxable amount — is calculated. Getting an independent valuation before you negotiate helps ensure the trade-in credit reflects your car's real market value rather than a lowball dealer offer.
Loan Term: 36 vs. 48 vs. 60 vs. 72 vs. 84 Months
| Term | Monthly Payment | Total Interest Paid | Equity Buildup |
|---|---|---|---|
| 36 months | Highest | Lowest | Fastest |
| 48 months | High | Low | Fast |
| 60 months | Moderate | Moderate | Average |
| 72 months | Lower | High | Slow |
| 84 months | Lowest | Highest | Slowest — high risk of negative equity |
Stretching a loan to 72 or 84 months lowers the monthly payment, which is why dealers promote it, but it also means paying interest for years longer and a much higher risk of owing more than the car is worth if you need to sell or trade it in early. Use the loan term fields in the calculator above to compare terms side by side before you decide.
The Impact of Extra Payments on Your Auto Loan
Because interest on an amortized car loan is front-loaded, extra payments made early in the loan term cut total interest disproportionately compared to extra payments made later. Even a modest recurring extra payment of $50-$100 a month can shave months off your payoff timeline and save meaningful money in interest. Use the "Extra Monthly Payment" field above to see your own numbers.
Should You Refinance Your Auto Loan?
Refinancing replaces your current car loan with a new one, ideally at a lower rate. It's usually worth exploring if your credit score has improved since you financed, if market rates have dropped, or if you originally financed through a dealer at a rate higher than banks or credit unions currently offer. Refinancing rarely makes sense very late in the loan term, since most of the interest has already been paid and closing costs may outweigh the savings.
Tips to Get the Best Auto Loan Rate
- Check your credit score and credit report for errors before you apply — even a small score bump can unlock a better rate tier.
- Get pre-approved by a bank or credit union before visiting a dealership so you can compare that offer against dealer financing.
- Shop multiple lenders within a short window (typically 14 days) — credit bureaus generally treat clustered auto loan inquiries as a single inquiry.
- Choose the shortest term you can comfortably afford — it minimizes total interest and builds equity faster.
- Negotiate the vehicle price and financing terms separately; a low advertised APR can hide a higher negotiated price.
- Put down as much as you reasonably can, and use a trade-in appraisal from more than one source.
Common Mistakes to Avoid When Financing a Car
- Focusing only on the monthly payment. A lower payment from a longer term can cost thousands more in total interest.
- Skipping pre-approval. Walking in without a benchmark rate leaves you negotiating blind against dealer financing.
- Rolling over negative equity. Adding what you still owe on a trade-in to a new loan inflates your amount financed and can trap you in a cycle of upside-down loans.
- Skipping the sales tax and fees in your budget. These can add hundreds or thousands of dollars to your amount financed.
- Not reading the contract for prepayment penalties or add-ons. Extended warranties and add-on products are often financed into the loan and increase your total interest.
Frequently Asked Questions
Q: How is a car payment calculated?
A: A car payment is calculated by first finding your amount financed (vehicle price plus sales tax, minus your down payment and trade-in value), then applying the standard amortization formula using your interest rate and loan term to spread that amount into equal monthly payments.
Q: What credit score do I need for the best auto loan rate?
A: Lenders generally reserve their lowest advertised APRs for borrowers with credit scores of 720 and above. Scores in the 660-719 range still qualify for reasonable rates, while scores below 660 typically face higher APRs or require a larger down payment.
Q: How much should I put down on a car?
A: A common guideline is at least 10-20% of the vehicle's price for a new car and 10% for a used car. A larger down payment lowers your amount financed, reduces total interest, and helps you avoid being upside-down on the loan as the car depreciates.
Q: Does my trade-in reduce the amount I finance?
A: Yes. Your trade-in's appraised value is subtracted from the vehicle's price before the loan amount is calculated, directly lowering both your amount financed and, in many states, the sales tax you owe on the purchase.
Q: Is a 72 or 84 month auto loan a good idea?
A: Longer terms like 72 or 84 months lower your monthly payment but substantially increase total interest paid and raise the risk of owing more than the car is worth. Shorter terms of 36-60 months cost less overall and build equity faster.
Q: Should I get pre-approved before visiting a dealership?
A: Yes. Pre-approval from a bank or credit union gives you a known interest rate and budget ceiling, letting you negotiate the vehicle price as a cash-equivalent buyer and compare that offer directly against the dealer's financing.
Q: Does sales tax get added to my auto loan?
A: In most states, sales tax is rolled into the amount financed unless paid up front. Many states also apply a trade-in tax credit, meaning tax is charged only on the difference between the vehicle price and your trade-in value.
Q: Can I pay off my auto loan early without a penalty?
A: Most auto loans from banks and credit unions can be paid off early without penalty, and doing so reduces total interest since car loan interest is calculated on the remaining balance. A small number of subprime or dealer-financed loans include prepayment penalties, so check your contract.
This calculator provides estimates for informational purposes only and does not constitute financial advice. Actual loan terms, rates, taxes, and fees vary by lender, dealer, and state. Consult a licensed financial professional or your lender for guidance specific to your situation.