How the amount financed is built
An auto loan can include sales tax and financed fees in addition to the cash price left after a down payment and trade-in. Vehicle tax rules vary by jurisdiction: some places allow a trade-in credit against the taxable price, while others tax the full selling price. Enter the taxable purchase amount shown on the deal sheet or supplied by the tax authority.
Amount financed = vehicle price − down payment − trade-in + sales tax + financed fees
Monthly payment = P × r ÷ [1 − (1 + r)^−n]
Total interest = monthly payment × months − amount financed
Example
A $30,000 vehicle, $3,000 down, no trade-in, a $30,000 taxable amount, 6% sales tax, and $0 of financed fees produces a $28,800 loan: $27,000 after the down payment plus $1,800 of tax. At 6.5% for 60 months the payment is about $563.51. If a jurisdiction taxes only $25,000 after a $5,000 trade-in credit, enter $25,000 as the taxable amount.
What this payment leaves out
The rate is the contract rate you type, not a live lender quote. Gap insurance, warranties, registration, documentation charges, and dealer add-ons may be financed or taxed differently. Copy the taxable amount, tax rate, and financed fees from the deal sheet when available; this page does not load a 50-state tax table.