Auto Loan Calculator

What this auto loan calculator does

It works out what a car will actually cost you each month once the sticker price has been adjusted for tax, your deposit and any vehicle you are trading in. Dealers tend to negotiate around the monthly payment because it is the number buyers feel, but that figure can be made to look attractive simply by extending the term. Seeing the amount financed and the total interest alongside it keeps the real cost visible.

The formula behind it

The financed amount is price + sales tax − down payment − trade-in value. That balance is then amortised with the standard payment formula P × r × (1 + r)ⁿ / ((1 + r)ⁿ − 1), where r is the monthly rate and n the number of monthly payments. Tax is normally charged on the vehicle price, and in many jurisdictions a trade-in reduces the taxable amount.

How to use this calculator

Enter the vehicle price, your down payment, any trade-in value, the sales tax rate, the interest rate and the term in years. The result shows the monthly payment, the amount financed and the total interest. Run the same car over three, five and seven years to see how much a longer term really costs.

Before you sign

Arrange financing with your own bank first — a quoted rate in hand is the strongest position from which to assess a dealer's offer. A deposit of around 20% lowers both the payment and the risk of owing more than the car is worth, which matters because a new vehicle loses value fastest in its first two years. Budget separately for insurance, servicing and fuel; these routinely add a substantial amount to the monthly figure this calculator returns.