Auto Loan Payment Calculator with Down Payment

This auto loan payment calculator helps you determine your monthly payments when you include a down payment. By adjusting the loan amount, interest rate, loan term, and down payment, you can see how these factors affect your monthly payments and total interest paid.

How to Use This Calculator

To calculate your auto loan payments with a down payment:

Enter the total loan amount you're requesting (before down payment).
Enter your down payment amount.
Input the annual interest rate (APR).
Select the loan term in years.
Click "Calculate" to see your monthly payment and total interest.

The calculator will show you the adjusted loan amount after your down payment, your monthly payment, and the total interest you'll pay over the life of the loan.

Formula Explained

The auto loan payment calculator uses the standard loan payment formula:

Loan Payment Formula

M = P [ i(1 + i)^n ] / [ (1 + i)^n - 1 ]

Where:

M = Monthly payment
P = Principal loan amount (after down payment)
i = Monthly interest rate (annual rate divided by 12)
n = Number of payments (loan term in years multiplied by 12)

Before applying the formula, the calculator subtracts your down payment from the total loan amount to determine the principal amount (P) that will be financed.

Worked Example

Let's say you're looking to finance a $25,000 car with a $5,000 down payment, at an annual interest rate of 5% over 5 years.

Adjusted loan amount: $25,000 - $5,000 = $20,000
Monthly interest rate: 5% ÷ 12 = 0.4167% or 0.004167
Number of payments: 5 years × 12 = 60 months
Using the formula: M = $20,000 [ 0.004167(1 + 0.004167)^60 ] / [ (1 + 0.004167)^60 - 1 ]
Calculated monthly payment: $362.50
Total interest paid: $3,750.00

This example shows that with a $5,000 down payment, your monthly payment is $362.50 and you'll pay $3,750 in interest over the life of the loan.

Frequently Asked Questions

How does a down payment affect my monthly payments?

A down payment reduces the principal amount you need to finance, which typically lowers your monthly payments. The more you put down, the less you'll pay each month.

Is the interest rate the same as the APR?

Yes, the interest rate used in this calculator is typically the Annual Percentage Rate (APR) quoted by lenders, which includes all fees and costs.

Can I pay extra each month to pay off the loan faster?

Yes, making additional payments can help you pay off your loan earlier and save on interest. You can use our extra payment calculator to see how much you'll save.