Estimate your monthly car payment, total interest, and full payback cost. Includes down payment, trade-in tax credit, sales tax, and a complete amortization schedule.
An auto loan calculator estimates your monthly car payment based on the vehicle price, down payment, trade-in value, sales tax, interest rate (APR), and loan term. It uses the standard amortization formula to show not just your payment, but the total interest you'll pay over the life of the loan. For example, a $30,000 loan at 6.5% APR over 60 months costs about $587/month and roughly $5,200 in total interest.
Enter your numbers below. Results update instantly, including a full amortization schedule.
| Month | Payment | Principal | Interest | Balance |
|---|
Estimate your real car payment in under two minutes:
Auto loans use amortization — the same math as mortgages. Each fixed monthly payment covers the interest accrued that month, with the remainder going toward the principal. Early payments are mostly interest; later payments are mostly principal.
The loan amount itself is built from several pieces:
You're buying a $35,000 vehicle with $5,000 down, a $2,000 trade-in, 8% sales tax, 6.5% APR, over 60 months. (Assume your state gives a trade-in tax credit.)
Step 1: Calculate taxable amount and tax
Step 2: Calculate loan amount
Step 3: Apply the payment formula
Step 4: Total interest
Monthly payment: $599.51 · Total interest: $5,330 · You pay $5,330 just to borrow the money
Here's a money-saving detail many buyers — and most calculators — overlook: in most US states, trading in your old car reduces the sales tax on your new one.
You only pay sales tax on the difference between the new car's price and your trade-in value. On a $35,000 car with a $10,000 trade-in at 8% tax, you'd be taxed on $25,000 instead of $35,000 — a savings of $800 just from the tax credit, on top of the trade-in value itself.
A few states — including California, Hawaii, Kentucky, Michigan (partial), and Virginia — do not give a full trade-in tax credit and tax the full purchase price. Check your state's rules. The calculator above applies the trade-in credit by default, which is correct for most states.
Dealers love to advertise low monthly payments — and the easiest way to lower a payment is to stretch the loan term. But a longer term is one of the most expensive mistakes a car buyer can make.
Here's the same $30,640 loan at 6.5% APR across different terms:
| Term | Monthly Payment | Total Interest | vs 36 months |
|---|---|---|---|
| 36 months | $939 | $3,179 | — |
| 48 months | $726 | $4,239 | +$1,060 |
| 60 months | $600 | $5,330 | +$2,151 |
| 72 months | $515 | $6,453 | +$3,274 |
| 84 months | $456 | $7,610 | +$4,431 |
Going from 36 to 84 months drops the payment by $483/month — but costs you an extra $4,431 in interest and keeps you in debt for four more years. The lower payment feels good; the total cost hurts.
Finance for the shortest term you can comfortably afford. Many experts recommend a maximum of 48 months for a used car and 60 months for a new one. If you can only afford the payment by stretching to 72-84 months, that's often a sign the car is too expensive for your budget.
A car is a depreciating asset — it loses value the moment you drive it off the lot, often 20% in the first year. If your loan balance is higher than the car's value, you're "underwater" or have "negative equity."
Long loan terms and small down payments make this worse — you pay down principal slowly while the car depreciates quickly. Being underwater is a problem if you need to sell or if the car is totaled, because insurance only pays the car's value, leaving you to cover the gap. A larger down payment and shorter term protect you from this.
Your credit score is the single biggest factor in the interest rate you're offered. The difference between excellent and poor credit can mean thousands of dollars over the life of a loan. Here's a general illustration of how rate tiers work (actual rates vary by lender and market conditions):
| Credit Tier | Score Range | Relative Rate |
|---|---|---|
| Superprime | 781-850 | Lowest available |
| Prime | 661-780 | Competitive |
| Nonprime | 601-660 | Noticeably higher |
| Subprime | 501-600 | High |
| Deep subprime | 300-500 | Highest |
Before car shopping, check your credit score and consider getting pre-approved by your own bank or a credit union. This gives you a baseline rate to compare against dealer financing — and dealers will often try to beat it, saving you money. Improving your score even one tier before buying can save thousands.
Your monthly loan payment is only part of what a car actually costs. Smart buyers budget for the full picture:
A useful guideline is the 20/4/10 rule: put at least 20% down, finance for no more than 4 years, and keep total monthly vehicle costs (payment + insurance + fuel) under 10% of your gross income.
An auto loan payment is calculated using the amortization formula: M = P × r(1+r)^n / ((1+r)^n − 1), where P is the loan amount (price plus tax minus down payment and trade-in), r is the monthly interest rate (APR divided by 12), and n is the number of months. The calculator does this automatically and also shows total interest and a full payment schedule.
A good auto loan rate depends heavily on your credit score and whether the car is new or used. As of 2026, borrowers with excellent credit (720+) often qualify for the lowest advertised rates, while those with poor credit pay significantly more. New car loans typically have lower rates than used car loans. Always compare offers from banks, credit unions, and dealers before signing.
A common guideline is 20% down for a new car and 10% for a used car. A larger down payment reduces your loan amount, lowers your monthly payment, reduces total interest, and helps you avoid being "underwater" (owing more than the car is worth). Even if 20% isn't possible, more down is almost always better financially.
Not usually. A longer term (like 72 or 84 months) lowers your monthly payment but dramatically increases the total interest you pay, and keeps you underwater on the loan longer. A shorter term (36-48 months) costs more per month but saves significant money overall and builds equity faster. Choose the shortest term you can comfortably afford.
In most US states, yes — you only pay sales tax on the difference between the car's price and your trade-in value, which can save hundreds or thousands of dollars. However, a few states (like California and Virginia) tax the full purchase price regardless of trade-in. Check your state's rules, and use the trade-in field in the calculator to see the impact.
The monthly payment shown by this calculator covers principal and interest on the loan only. It does not include insurance, registration, maintenance, fuel, or optional add-ons like extended warranties and gap insurance. Budget for these separately — they can add a significant amount to your true monthly cost of ownership.
Yes — just set the down payment field to $0. Be aware that financing the full price (plus tax) means a larger loan, higher payments, more total interest, and a greater chance of being underwater. Zero-down loans are possible but generally more expensive over time. Even a small down payment helps.
No. All calculations happen entirely in your browser. Your numbers stay on your device — nothing is sent to our servers, and no data is stored after you close the page.
This calculator provides estimates for educational purposes only. Actual loan terms, rates, taxes, and fees vary by lender, state, and individual circumstances. It is not financial advice. Always review the full terms of any loan offer and consult a financial professional for personalized guidance.