Your monthly car payment, all-in.
| # | Payment | Principal | Interest | Balance |
|---|
The number the calculator wants is the amount financed, not the sticker price. Start with the negotiated price, add sales tax, title, registration, and any dealer fees you are rolling into the loan, then subtract your down payment and the trade-in credit. What remains is what you actually borrow, and it is what your payment is built from.
Enter the APR from an offer or preapproval rather than a rate you have seen advertised, since advertised rates describe the strongest credit profiles. Auto terms usually run 36 to 84 months. Because the car itself secures the loan, auto APRs are typically lower than unsecured personal-loan rates for the same borrower.
Illustrative example, not a market quote: financing $28,000 at 7% over 60 months is $554.43 a month, $5,266.01 of total interest, and $33,266.01 paid in all.
Hold the amount and term fixed and change only the APR. These rates are examples picked to show the size of the effect, not quoted averages.
| Example APR | Monthly payment | Total interest | Total paid |
|---|---|---|---|
| 5% | $528.39 | $3,703.67 | $31,703.67 |
| 7% | $554.43 | $5,266.01 | $33,266.01 |
| 9% | $581.23 | $6,874.04 | $34,874.04 |
Four percentage points of APR is $52.84 a month on this loan and $3,170.36 over five years. That is why a preapproval from your own bank or credit union is worth having before you sit down at a dealership: it turns the rate into something you can compare instead of accept.
Lenders usually price used-car loans above new-car loans. The collateral is older, its value is harder to pin down, and it has less life left over the term. Model-year and mileage caps are common, and some lenders shorten the maximum term on older vehicles.
To size the gap, here is the same $28,000 financed over 60 months at two illustrative rates, 6.5% and 9.5%. The lower rate is $547.85 a month; the higher one is $588.05, a difference of $40.20 a month and $2,412.00 in total interest. A used car still usually costs less overall because the price is lower, but the rate advantage runs the other way, and that is worth pricing rather than assuming.
| Term | Monthly payment | Total interest | Total paid |
|---|---|---|---|
| 36 months | $864.56 | $3,124.11 | $31,124.11 |
| 48 months | $670.49 | $4,183.75 | $32,183.75 |
| 60 months | $554.43 | $5,266.01 | $33,266.01 |
| 72 months | $477.37 | $6,370.80 | $34,370.80 |
| 84 months | $422.60 | $7,497.98 | $35,497.98 |
Stretching $28,000 at 7% from 36 months to 84 months drops the payment by $441.96 a month and raises total interest by $4,373.87. The long term also keeps your balance high for longer: after three years of payments, the 84-month version still owes $17,647.65 while the 60-month version owes $12,383.33.
That balance gap is what people mean by being underwater. If the car is worth less than the balance and it is totaled or you need to sell, you owe the difference in cash. Gap insurance covers that shortfall on some loans and leases; whether you need it depends on the size of your down payment and the term you chose.
Money down does two things at once: it cuts the amount financed and it starts you closer to positive equity. On the example loan, putting $4,000 more down takes the payment from $554.43 to $475.23 and total interest from $5,266.01 to $4,513.73, saving $752.29 in interest on top of the $4,000 you did not borrow.
If you are trading in a car you still owe money on, negative equity rolled into the new loan is added to the amount financed. Enter the combined figure above, not the price of the new car, or the payment you see will be optimistic.
Dealer financing is usually arranged through lenders the dealership works with, and the rate presented to you can include a markup over what the lender approved. That is legal and common, and it is also negotiable. Manufacturer promotional rates on new cars run the other way and are sometimes below what any bank would write, though they are often offered as an alternative to a cash rebate, so the promotional rate and the discount are a choice rather than a pair.
The practical move is to arrive with a preapproval in hand. It costs nothing to have a second number, it converts the finance conversation into a comparison, and it separates the price of the car from the price of the money. Price the car first, settle the trade-in second, and discuss financing last, since a single monthly payment figure can hide movement in any of the three.
If your credit improves or rates fall, refinancing replaces the remaining balance with a new loan. On the example, after two years of payments the balance is $17,956.14 with 36 months left, and staying put costs $2,003.47 in remaining interest. Refinancing that same balance over the same 36 months at an illustrative 5.5% gives a payment of $542.20 and $1,563.13 of interest, a saving of $440.34 before any fees.
Two cautions. Refinancing into a longer term can raise the total cost even at a lower rate, because you are paying interest for more months; enter both versions above to compare. And title or lien-transfer fees, which vary by state and lender, come off whatever you save.
A personal loan does not put a lien on the car, which matters for private-party sales and vehicles too old for a lender to finance. It usually costs more because it is unsecured. On an identical $20,000 over 60 months at illustrative rates of 7% and 12%, the unsecured version runs $48.86 more a month and $2,931.90 more in total interest. The full auto versus personal comparison walks through when each one fits.
Whichever you use, extra payments still shorten it. Adding $100 a month to the example auto loan clears it 10 months early and saves $959.91 in interest.
If you are rolling them into the financing, yes: enter the full amount you will actually borrow. If you are paying them in cash at signing, leave them out.
Yes. Stretching the same amount over more months lowers the payment but raises total interest, and increases the time you owe more than the car is worth.
Use the APR from an actual offer or preapproval. Rates vary widely with credit score, term, and whether the car is new or used, so any single typical number would mislead.
The collateral is older and its resale value is less predictable, so lenders price the added risk into the rate and often cap the term or the model year they will finance.
No. It calculates the loan payment only. Insurance, fuel, registration renewals, and maintenance are real costs of owning the car, but they are not part of the amortization.