Loans
Auto Loan Calculator
Get your real car payment — not the dealer's teaser number. This calculator includes what others skip: sales tax (with the trade-in credit most states allow), fees, your down payment, and even negative equity if you owe more than your trade is worth. Then it shows the vehicle's true total cost.
Formula shown below · Tested against worked examplesHow we verify
If you owe more than the trade is worth, the difference rolls into the new loan.
Most states tax the price minus your trade-in value.
Monthly payment: $609.55
Monthly payment
$609.55
- Amount financed
- $30,420
- Sales tax
- $1,920
- Total interest
- $6,153
- True total cost of the car
- $40,573
Price + tax + fees + all the interest.
Compare scenariosTry three values of one input
| Vehicle price | |||
|---|---|---|---|
| Monthly payment | $545.83 | $609.55+$63.72 | $673.28+$127.45 |
| Amount financed | $27,240 | $30,420+$3,180 | $33,600+$6,360 |
| Sales tax | $1,740 | $1,920+$180 | $2,100+$360 |
| Total interest | $5,510 | $6,153+$643 | $6,796+$1,286 |
| True total cost of the car | $36,750 | $40,573+$3,823 | $44,396+$7,646 |
Every other input stays at the value you set above — currently $32,000 for vehicle price. Differences are measured against the first column.
Saved scenariosSave this calculation
Saved in this browser only — no account, and nothing is sent to us. Clearing your browser data deletes them.
How this calculator works
Amount financed = price + sales tax + fees + any balance owed on your trade-in − trade-in value − down payment. Sales tax applies to the price minus trade-in (the rule in most states — toggle-able assumption stated here for transparency).
The loan amortizes in exact cents at your APR. True total cost sums the price, tax, fees, and all interest — the number to compare across cars and terms. Insurance, fuel, and maintenance are extra.
Formula
P = (price − down − trade-in) + fees
M = P × i(1+i)ⁿ ÷ ((1+i)ⁿ − 1)- P
- Amount financed
- M
- Monthly payment
- i
- Monthly rate: APR ÷ 12
- n
- Term in months
Most auto loans are simple-interest: interest accrues daily on the outstanding balance, so paying early genuinely reduces the total. Sales tax and fees are financed unless paid up front, which is why the amount financed can exceed the sticker price.
What this assumes
- Sales tax and fees are financed unless you pay them separately, which is why the amount financed can exceed the sticker price.
- A simple-interest loan: interest accrues daily on the outstanding balance, so paying early genuinely reduces the total.
- No insurance, fuel, maintenance or depreciation. Those frequently exceed the payment itself over the life of the car.
What changes this number
- Term length
- A 72-month term makes almost any car look affordable and extends the period during which you owe more than the vehicle is worth.
- Down payment and trade-in
- Both reduce the amount financed directly, and both shorten the window of negative equity.
- Credit score
- The spread between good and poor credit on an auto loan is commonly several percentage points, which is thousands of dollars over five years.
A worked example
Take the new suv: $38k, 10% down, 60 months scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.
What you enter
- Vehicle price
- $38,000
- Down payment
- $3,800
- Term
- 60 months
What it returns
- Monthly payment
- $741.00
- Amount financed
- $36,980
- Sales tax
- $2,280
- Total interest
- $7,480
- True total cost of the car
- $48,260
Sources
This calculator uses no external data — the result follows entirely from the formula above and the values you enter, so there is nothing to cite beyond the arithmetic.
Calculator last reviewed August 8, 2026. How we verify
Try an example
Frequently asked questions
What's a good interest rate on a car loan?
It depends on credit tier and whether the car is new or used: top-tier borrowers on new cars have recently seen roughly 5–7% APR, while deep subprime used-car loans can exceed 15–20%. Credit unions frequently beat dealer financing — get pre-approved before you shop.
How does a trade-in reduce sales tax?
In most states you pay sales tax only on the difference between the new car's price and your trade-in value. Trading in an $8,000 car against a $32,000 purchase at 6% saves $480 in tax on top of the $8,000 credit — a real advantage over selling privately in those states.
Is a 72- or 84-month loan a bad idea?
Long terms buy a lower payment at a triple cost: more total interest, years of being 'underwater' (owing more than the car's value), and often a higher rate. If the payment only works at 84 months, the honest signal is that the car is too expensive.
What is negative equity?
Owing more on your trade-in than it's worth. Dealers will happily roll the shortfall into your new loan — this calculator shows exactly what that does to the amount financed. Rolling debt from the last car into the next one compounds quickly; break the cycle when you can.
How much should I put down on a car?
A common guideline is 20% on a new car (10% used) — enough to absorb first-year depreciation so you're never underwater. Larger down payments also shrink the interest you pay and can qualify you for better rates.
What is the monthly payment on a $35,000 car?
With $5,000 down at 7% over 60 months, the payment is $665.32 and the total interest is $6,319. Including sales tax and fees, the true total cost of that car comes to about $43,919 — roughly a quarter more than the sticker price.
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Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.