Finance calculators

Car loan calculator

Amount financed, monthly payment, total interest and total cost with down payment, trade-in, sales tax and fees.

Inputs

Vehicle priceDown paymentTrade-in valueSales tax%FeesFinance the feesInterest rate (APR)%Term

Results

Methodology

Conventions

Sales tax is charged on the vehicle price less the trade-in value, as in most US states.
Fees are either financed or paid upfront. Monthly payments at the nominal annual rate divided by 12.
Total cost is everything you pay: the down payment, all loan payments and any fees paid upfront.

References

Kellison, The Theory of Interest, ch. 3 and 5

Formulas

Sales tax: T = s \cdot (\text{price} - \text{trade-in})
Amount financed: L = \text{price} + T + \text{fees} - \text{down} - \text{trade-in}
Monthly payment: A = L \cdot \frac{i}{1 - (1 + i)^{-n}},\quad i = r/12