Auto Loan Calculator
Monthly car payment, total interest, and total cost of the vehicle.
Enter vehicle price, down payment, trade-in value, interest rate, term, and sales tax. Get your monthly payment and total cost of the loan.
How auto loan math works
The monthly payment uses the standard amortization formula (same as a mortgage, but typically in months instead of years). Each payment includes interest on the current balance plus a portion that reduces the principal. Early payments are mostly interest; later payments are mostly principal.
What gets financed
Your loan amount equals: vehicle price MINUS down payment MINUS trade-in value PLUS sales tax (if rolled into the loan, which is common). Some buyers pay tax separately at signing; others finance it. This calculator assumes financed.
Loan terms (months)
- 36 months (3 years): highest payment, lowest total interest
- 48 months (4 years): common balance point
- 60 months (5 years): standard new car loan
- 72 months (6 years): common for higher-priced vehicles
- 84 months (7 years): very long; you may owe more than the car is worth for years
The 20/4/10 rule
A common financial rule of thumb: put at least 20 percent down, finance for no longer than 4 years, and keep total transportation costs (loan, insurance, fuel, maintenance) under 10 percent of gross income. If this calculator's monthly payment alone is over 10 percent of your monthly gross, the car may be more than you can comfortably afford.
What this calculator does NOT include
Title and registration fees, dealer documentation fees, gap insurance, extended warranties, or maintenance and fuel costs. These typically add 2-5 percent to the total cost of ownership in year one and continue thereafter.