What car payment results after down payment, trade-in and sales tax?
An auto-loan payment begins with the amount financed, not merely the sticker price. Down payment and trade-in reduce financing, while sales tax can increase it depending on the entered treatment.
Vehicle balance followed by loan amortisation
Tax = Price × Sales tax% ÷ 100Amount financed = Price + Tax − Down payment − Trade inPayment = Amount financed × i ÷ [1 − (1 + i)⁻ⁿ]Price, trade-in, tax and down payment
The default example builds the financed balance from vehicle price, tax, down payment and trade-in before applying the amortising loan formula.
Illustrative inputs; currency amounts below use USD. Rates and prices are assumptions, not live quotes.
- Vehicle price
- $32,000.00
- Down payment
- $5,000.00
- Trade in value
- $0.00
- Sales tax
- 0%
- Annual interest rate
- 7.5%
- Term in years
- 5
Step-by-step calculation
- Sales tax = 32,000 × 0 ÷ 100 = 0. Amount financed = 32,000 + 0 − 5,000 − 0 = 27,000.
- Use monthly rate 0.00625 and 60 payments in the amortisation formula to get 541.024612 per month.
- Loan interest = payment × months − financed amount = 5,461.476725. Total shown also includes down payment and trade-in value: 37,461.476725.
Intermediate figures are rounded for reading. Results use the full calculation precision.
Loan payment versus total vehicle cost
Monthly payment responds to both financing amount and loan terms. Total vehicle cost also includes cash or trade value contributed outside the loan.
Dealer items missing from a simple quote
Dealer quotes may include registration, documentation fees, add-ons or negative trade equity. Those amounts must be reflected in an input to appear in the result.
- Tax is calculated from the base represented in the formula.
- The loan uses a fixed annual rate and monthly payments.
- Dealer fees, insurance, rebates and negative equity are excluded.
Calculations related to auto loan
The following tools examine neighbouring parts of the same calculation without changing the inputs or assumptions used above.
References
Sources and conventions
- CFPB: loan amortisation
Explains how payments are split between interest and principal; actual agreements may use different timing or fees.
Quick answers
Frequently asked questions
Does a trade-in reduce the amount financed?
Yes. The entered trade-in value is subtracted along with the down payment.
Is sales tax calculated before the down payment?
Yes. This formula applies the tax rate to vehicle price, then subtracts down payment and trade-in.
Are dealer fees and insurance included?
No. Only the displayed price, tax, down payment, trade-in, rate and term inputs are used.
Calculation method and limitations · Report an error
Educational content only. This guide is not financial advice.