Auto Loan Amortization Calculator

An auto loan amortization calculator helps you understand how your car loan payments break down over time. It shows the principal, interest, and remaining balance for each payment, helping you plan your budget and track your progress toward paying off your car.

How Auto Loan Amortization Works

Amortization is the process of paying off a loan through scheduled payments that cover both interest and principal. For auto loans, these payments are typically monthly. The amortization schedule shows how each payment affects the loan balance and interest charges.

Key Components of Amortization

The key components of an auto loan amortization schedule include:

Principal: The portion of each payment that reduces the loan balance.
Interest: The cost of borrowing the money, calculated as a percentage of the remaining balance.
Remaining Balance: The amount still owed after each payment.
Total Interest Paid: The cumulative interest paid over the life of the loan.

Monthly Payment Formula

The monthly payment (PMT) for an auto loan can be calculated using the formula:

PMT = P × [r(1 + r)ⁿ] / [(1 + r)ⁿ - 1]

Where:

P = Principal loan amount
r = Monthly interest rate (APR ÷ 12)
n = Number of payments (Loan term in years × 12)

Amortization Schedule

An amortization schedule is a table that shows how each payment affects the loan balance. It typically includes columns for the payment number, payment amount, principal portion, interest portion, and remaining balance.

Payment #	Payment Amount	Principal	Interest	Remaining Balance
1	$450.00	$250.00	$200.00	$19,750.00
2	$450.00	$255.00	$195.00	$19,495.00
3	$450.00	$260.00	$190.00	$19,235.00

As you can see, each payment reduces the remaining balance while increasing the principal portion paid. The interest portion decreases over time as the loan balance decreases.

Worked Example

Let's look at an example to see how the auto loan amortization calculator works. Suppose you take out a $20,000 auto loan with a 5% annual interest rate and a 5-year term.

Step 1: Calculate the Monthly Payment

Using the monthly payment formula:

Principal (P) = $20,000
Annual interest rate = 5% → Monthly rate (r) = 5% ÷ 12 = 0.4167%
Loan term = 5 years × 12 = 60 months (n)

PMT = $20,000 × [0.004167(1 + 0.004167)⁶⁰] / [(1 + 0.004167)⁶⁰ - 1]

PMT ≈ $450.00

Step 2: Create the Amortization Schedule

The first few payments of the amortization schedule would look like this:

Payment #	Payment Amount	Principal	Interest	Remaining Balance
1	$450.00	$250.00	$200.00	$19,750.00
2	$450.00	$255.00	$195.00	$19,495.00
3	$450.00	$260.00	$190.00	$19,235.00

Step 3: Analyze the Results

From this example, you can see that:

The monthly payment is $450.00.
The first payment includes $250.00 toward principal and $200.00 in interest.
By the end of the first year, you'll have paid $5,400 in interest.
The loan will be fully paid off after 60 payments.

FAQ

What is the difference between APR and interest rate?: The APR (Annual Percentage Rate) is the total cost of borrowing, including all fees and points, while the interest rate is the cost of borrowing without fees.
How does making extra payments affect amortization?: Making extra payments reduces the principal balance faster, lowering the total interest paid and shortening the loan term.
Can I refinance my auto loan?: Yes, refinancing can lower your interest rate and monthly payments, but it may require a good credit score and closing costs.
What happens if I miss a payment?: Missing a payment can result in late fees, higher interest charges, and potential damage to your credit score.
How do I calculate the total interest paid on my loan?: Multiply the monthly payment by the number of payments, then subtract the loan amount to find the total interest paid.