Auto Loan Calculator
Calculate monthly car payments and total cost of an auto loan.
What this calculator does
This auto loan calculator turns a vehicle price, a down payment, an APR, and a term in months into the monthly payment you will actually be quoted, plus the total cost across the full term. It runs two structures side by side: a standard amortizing loan that pays the vehicle off completely, and a balloon-style loan that defers a large final payment to keep the monthly figure low.
Seeing both at once matters because dealerships tend to negotiate on the monthly payment rather than the price. The total cost column is the honest comparison, and it is where a low monthly quote on a long term or a deferred balloon stops looking like a bargain.
When to use it
Use it before you walk into a dealership, not after. Working out what a payment you are comfortable with implies for vehicle price gives you a ceiling that survives contact with a salesperson. It is also the tool for comparing a credit union preapproval against the finance office's counteroffer, since the two will be quoted at different terms and only the total cost makes them comparable.
The second use is testing the term. Running 48, 60, and 72 months at the same price shows exactly what each extra year of financing costs, and whether stretching the term is buying you breathing room or just a more expensive car.
Understanding the inputs
Vehicle price should be your out-the-door number if you can estimate it — the negotiated price plus sales tax, title, registration, and dealer documentation fees — because that is what gets financed. Down payment includes cash plus any trade-in equity, but subtract negative equity you are rolling over from an existing loan rather than adding it.
APR is the rate you have been approved for, not the advertised rate, which typically applies only to superprime credit. Term in months drives the payment more than any other single input: the same loan at 72 months looks affordable and at 48 months looks expensive, while the underlying debt is identical.
How is this calculated?
Monthly Payment = P[r(1+r)^n]/[(1+r)^n-1] where P = Vehicle Price − Down Payment.
A worked example
Take a $34,000 vehicle with $4,000 down, leaving $30,000 financed at 7.5 percent APR over 60 months. The monthly payment comes to about $601, and the total of payments is roughly $36,068 — so the financing costs around $6,068 on top of the price.
Run the same deal as a balloon loan with a final payment set at 40 percent of the vehicle price, or $13,600. The monthly payment drops to roughly $414, saving about $187 a month. But at month 60 you still owe $13,600 in one lump. Unless the car is comfortably worth more than that, the low payment is a deferral, not a discount.
Limitations and assumptions
The calculator assumes a fixed APR, no dealer fees, and simple monthly amortization. It does not model sales tax by state, GAP insurance, extended warranties, negative equity rolled in from a trade, or manufacturer subvented rates tied to a specific model year. The balloon estimate uses a flat 40 percent of vehicle price rather than a lender's actual residual table.
It also says nothing about whether the car is worth the money. Insurance, maintenance, fuel, and depreciation frequently exceed the financing cost over five years. Use this for the loan question and a separate total-cost-of-ownership estimate for the buying decision.
Common Questions
- What credit score do I need for the best auto loan rate?
- Lenders bucket borrowers into tiers, and the advertised rate belongs to the top one. Superprime generally starts around a 781 FICO, prime around 661. The gap between tiers is real money: on a $30,000 loan, moving from near-prime to prime pricing routinely cuts three or four percentage points off the APR.
- Is a 72 or 84-month car loan a bad idea?
- It lowers the payment and raises almost everything else. Longer terms carry higher rates, and because cars depreciate faster than the loan amortizes, you spend years underwater — owing more than the car is worth. If you need 84 months to afford the payment, the honest answer is usually a cheaper car.
- What is the balloon option this calculator shows?
- It defers part of the price to a single lump sum at the end. The calculator estimates that final payment at 40 percent of the vehicle price and amortizes only the rest, which pulls the monthly figure down sharply. At the end you settle the balloon in cash, refinance it, or sell the car to cover it.
- Does this include sales tax, title, and dealer fees?
- No. It amortizes vehicle price minus down payment. Sales tax, title and registration, documentation fees, and any add-ons like GAP or an extended warranty are usually rolled into the financed amount at the dealership, which can add several thousand dollars. Enter your out-the-door price to get a realistic payment.
- How much should I put down on a car?
- Twenty percent on a new car and ten percent on a used one is the traditional guide, and the reason is depreciation rather than the payment. A new vehicle can lose roughly 20 percent of its value in year one, so a thin down payment puts you underwater immediately and makes an insurance total loss expensive.
- Should I take the 0% APR offer or the cash rebate?
- Run both. Zero percent financing and a rebate are usually mutually exclusive, so compare the total of payments at 0 percent on the full price against the total at your bank's rate on the discounted price. On short terms the rebate often wins; on long terms the free financing usually does.
- Is dealer financing worse than a credit union loan?
- Dealers arrange financing through lenders and may add a markup to the buy rate, historically capped around one to two percentage points. That is not automatically a bad deal — dealers also access subvented manufacturer rates. Get preapproved by a credit union first so you have a number the finance office has to beat.
- Can I refinance an auto loan later?
- Yes, and it is far simpler than a mortgage refinance — usually no appraisal and minimal fees. It works best if your credit score has improved or rates have fallen, and if the car is worth more than you owe. Lenders typically want loan-to-value under 120 percent and a vehicle under about ten years old.