Auto Loan CalculatorFree online financial calculator — instant results, no sign-up
Monthly car payment including trade-in, tax and fees.
Estimates only, based on the inputs and assumptions shown. This is not financial, investment, tax, or legal advice. Prices, rates and local rules may change; crypto scenarios do not predict returns. Confirm important decisions with a qualified professional.
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How the result changes with vehicle price
Each row below was calculated with this tool, keeping every other input at its default and changing only vehicle price from half to one and a half times the default value. Use it to see how sensitive the answer is before you enter your own numbers.
| Vehicle price ($) | Amount financed | Monthly payment | Total of payments |
|---|---|---|---|
| 17,500 | $14,525.00 | $284.20 | $17,051.90 |
| 26,250 | $23,887.50 | $467.39 | $28,043.18 |
| 35,000 (default) | $33,250.00 | $650.57 | $39,034.47 |
| 43,750 | $42,612.50 | $833.76 | $50,025.75 |
| 52,500 | $51,975.00 | $1,016.95 | $61,017.03 |
About the Auto Loan Calculator
This calculator estimates the monthly payment and total borrowing cost for a motor vehicle purchase. It incorporates purchase price, sales tax, documentation or dealer fees, down payment, and trade-in credit into the financed amount. Prospective car buyers can use it to compare financing terms across different vehicle prices and interest rates.
- Vehicle price
- The agreed-upon purchase price of the vehicle before taxes, dealer add-ons, or discounts, in dollars (typically $1,000 to $200,000).
- Down payment
- The upfront cash paid toward the purchase at the time of sale, in dollars.
- Trade-in value
- The net allowance or equity credited for your existing vehicle, in dollars.
- Sales tax
- The state or local vehicle sales tax percentage applied to the vehicle price (typically 0% to 12%).
- Fees
- Upfront administrative, documentation, registration, and title fees rolled into the loan, in dollars.
- Rate
- The annual interest rate (APR) charged by the lender, as a percentage (typically 2% to 25%).
- Term
- The length of the loan repayment period, entered in months (commonly 24, 36, 48, 60, 72, or 84).
Formula and method
P = Vehicle Price × (1 + Sales Tax / 100) + Fees − Down Payment − Trade-in Value r = Rate / 100 / 12 M = P × [r(1 + r)^n] / [(1 + r)^n − 1] Total Payments = M × n Total Interest = Total Payments − P
- PPrincipal amount financed
- rMonthly interest rate (annual rate divided by 12)
- nTotal loan term in months
- MFixed monthly loan payment
The tool first calculates the total financed principal by adding sales tax and upfront fees to the vehicle price, then subtracting cash down payment and trade-in equity. It then applies the standard fixed-rate amortization annuity formula using the monthly interest rate and total months. The total interest represents the difference between cumulative payments and the initial principal financed.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Vehicle price35000 $
- Down payment5000 $
- Trade-in value0 $
- Sales tax7 %
- Fees800 $
- Rate6.5 %
Results
- Amount financed$33,250.00
- Monthly payment$650.57
- Total of payments$39,034.47
- Total interest$5,784.47
How to use the Auto Loan Calculator
- 1Compute the taxable vehicle price and add flat fees to establish total initial acquisition cost.
- 2Deduct the down payment and trade-in value to determine the final amount financed.
- 3Convert the annual interest rate to a monthly decimal (rate / 1200) and calculate the fixed monthly payment using the amortization formula.
- 4Multiply the monthly payment by the term length to find total payments, then subtract the principal to obtain total interest.
Reading your result
The 'Amount financed' indicates the actual loan balance required to drive the car off the lot, inclusive of taxes and fees. Comparing the 'Monthly payment' and 'Total interest' helps evaluate whether extending the loan term lowers monthly strain at the expense of substantially higher long-term financing costs.
Limitations
The calculation applies sales tax to the full vehicle price before trade-in credit, whereas certain states only tax the difference after the trade-in allowance. It also assumes a fixed interest rate with equal monthly installments and does not factor in GAP insurance, dealer warranties, or pre-computed interest penalties.
Common questions
Does a trade-in reduce the sales tax on a car purchase?+
In many US states, trade-in credit reduces the taxable sales price, lowering sales tax owed. However, this calculator applies sales tax to the full purchase price, which reflects states without trade-in tax credits or situations where local rules tax the gross transaction price.
What is the impact of choosing a 72- or 84-month auto loan?+
Extending the loan term spreads the principal over more months, lowering each individual monthly payment. However, because interest accrues over a longer timeframe, the total interest paid increases significantly, and you risk owing more than the car is worth (negative equity).
Can dealer fees be paid in cash instead of financed?+
Yes. If you pay dealer fees and sales tax out of pocket at closing, enter 0 for fees and taxes in the calculator (or add that cash to your down payment) to model financing only the vehicle balance.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.