Auto Loan Calculator
Vehicle price ($), Down payment ($), and Trade-in ($) set the amount financed, which is floored at zero, before Interest rate (%) and Term (months) produce a monthly payment and total interest.
How to use
- Enter Vehicle price ($). The sample is 28000. Put the price you intend to finance from, not a payment.
- Enter Down payment ($) and Trade-in ($). The samples are 3000 and 0. Both are subtracted from the price.
- Enter Interest rate (%) as a yearly percent. The sample is 5.9. The script divides by 100 and then by 12.
- Enter Term (months). The sample is 60. A zero or empty term is treated as 1.
- Click Calculate. The large line is Monthly. The detail line is Amount financed, Total interest, and Total paid.
When it helps
Use it to compare a larger down payment, a higher trade-in, or a longer term against the same vehicle price. Amount financed is price minus down payment minus trade-in, and the payment is the standard amortizing payment on that remainder. Total interest is total paid minus the amount financed.
Sales tax, title, and dealer fees are not added. Estimate a single tax rate on the sales tax calculator, then add any tax you will finance into Vehicle price ($) yourself. A loan that is already a financed balance, with no price or trade-in, fits the loan calculator. A house price minus a down payment, with the term in years, fits the mortgage calculator.
Limits
The form does not ask for sales tax, title, registration, doc fees, or a negative equity payoff beyond what you type into the price. If down payment plus trade-in is greater than the vehicle price, amount financed is 0, not a cash-back loan. A zero interest rate divides that financed amount by the month count.
The result is arithmetic, not a dealer quote and not a lender quote. Credit tier, rebates, a residual value, and a lease are not on the form. Extra principal payments after month one are not modeled, so Total paid assumes every month stays at the calculated payment.
Questions
Does Trade-in ($) reduce the price before interest?
Yes. Amount financed is vehicle price minus down payment minus trade-in, and interest is computed only on that amount. A trade-in of 0 leaves the price minus the down payment.
What if the down payment is larger than the price?
The script uses the greater of zero and price minus down payment minus trade-in. The monthly line becomes 0. It will not show the lender owing you the surplus.
Should I type the monthly rate or the yearly rate?
Type the yearly Interest rate (%). A contract at 5.9 percent per year is 5.9 in the box, not 5.9 divided by 12. The division by 12 happens after you click Calculate.