What does it mean to be “underwater” on a car loan?

It means owing more on the loan than the car is currently worth, which happens more easily and for longer with small down payments and long loan terms, since cars depreciate faster than a long loan pays down principal early on.

How does a bigger down payment affect my car loan?

It reduces the loan amount directly, lowering both the monthly payment and total interest paid, and reduces the risk of owing more than the car is worth in the early months of the loan.

Car Payment Calculator

Calculate your monthly auto loan payment including tax, trade-in, and total cost of ownership.

Vehicle Price ($)

Down Payment ($)

Trade-In Value ($)

Sales Tax Rate (%)

Loan Term (months)

Interest Rate (% APR)

How to use

Enter the vehicle price (sticker price before tax).
Add your down payment and any trade-in vehicle value.
Enter your local sales tax rate — this is applied to the vehicle price.
Choose your loan term and enter your APR from your lender.
Click Calculate to see your monthly payment and total loan cost.
Enter your monthly take-home pay to check if this payment fits your budget.

About this Car Payment Calculator

A car loan's monthly payment depends on four factors working together: the loan amount (price minus down payment), the interest rate, and the loan term. Changing any one of them shifts both the monthly payment and the total interest paid over the life of the loan.

The trade-off between loan term and total cost

A longer loan term (72 or 84 months instead of 60) lowers the monthly payment but increases total interest paid, since interest accrues over more months. It also increases the risk of being "underwater" — owing more than the car is worth — for longer, since vehicles depreciate faster than a long loan pays down principal in the early years.

Why a down payment matters beyond the monthly payment

A larger down payment reduces the loan amount directly, lowering both the monthly payment and total interest. It also reduces the risk of being underwater early in the loan, since the car's value and the loan balance start closer together instead of the loan balance starting well above the car's actual worth.

Worked example

A $30,000 car with a $5,000 down payment leaves a $25,000 loan. At 6% APR over 60 months, that's roughly $483/month and about $3,980 in total interest. Stretching the same loan to 72 months drops the payment to roughly $415/month but raises total interest to about $4,880 — a lower monthly cost at a real long-term price.