See how your down payment affects monthly payments, total interest, and your equity position — side by side.
| Down Payment | Amount Down | Monthly Payment | Total Interest | Interest Saved |
|---|
Enter your vehicle price, interest rate, and loan term, then drag the slider to set your down payment percentage. The results show your monthly payment and total interest — plus a comparison table across common down payment levels so you can see the full picture before you commit.
A down payment is the cash you pay upfront when buying a car. It reduces the amount you need to borrow, which lowers your monthly payment and the total interest you'll pay over the life of the loan. It also determines your starting equity — how much of the car you actually own from day one.
A widely used guideline for car buying: put down at least 20%, finance for no longer than 4 years, and keep total monthly car costs (payment + insurance) below 10% of your gross monthly income. Following this rule keeps you in positive equity and avoids overextending your budget.
On a $35,000 car at 6.5% APR over 60 months, going from 0% down to 20% down saves you roughly $2,400 in total interest and cuts $130 off your monthly payment.
Financial experts generally recommend at least 20% down on a new car and at least 10% down on a used car. New cars depreciate rapidly — often 15–20% in the first year — so a larger down payment protects you from going underwater (owing more than the car is worth).
You're underwater on a loan — also called negative equity — when your remaining loan balance is higher than the car's current market value. This matters if you need to sell the car, trade it in, or if it gets totaled. With a small down payment, you can be underwater for the first 2–3 years of a typical loan.
Yes, many lenders offer zero-down financing, and some dealers actively promote it. But it comes at a cost: higher monthly payments, more total interest, and immediate negative equity. Zero-down makes most sense when you have a high credit score, a short loan term, or access to a 0% promotional APR offer.
Your trade-in value counts toward your down payment. If your current car is worth $6,000 and you owe nothing on it, that $6,000 reduces the amount you need to finance — same effect as putting $6,000 cash down. If you still owe money on your trade-in, the remaining balance gets rolled into your new loan.