Auto Loan Calculator with Interest and Principal

How to Use This Calculator

Using this auto loan calculator is simple. Follow these steps:

1. Enter the loan amount you're borrowing (e.g., $25,000).
2. Input the annual interest rate (e.g., 4.5%).
3. Select the loan term in years (e.g., 5 years).
4. Click the Calculate button to see your monthly payment, total interest, and principal breakdown.
5. Review the amortization schedule chart to see how your loan balances over time.

The calculator will display your monthly payment, total interest paid, and principal repayment. You can also view a chart showing how your loan amortizes over time.

Formula Used

The monthly payment for an auto loan is calculated using the standard loan payment formula:

Total interest paid is calculated by multiplying the monthly payment by the number of payments and subtracting the principal loan amount.

Worked Example

Let's calculate a $25,000 auto loan with a 4.5% annual interest rate over 5 years (60 months).

1. Convert the annual rate to a monthly rate: 4.5% ÷ 12 = 0.375% or 0.00375 in decimal.
2. Plug the values into the formula:

   Monthly Payment = $25,000 × [0.00375(1 + 0.00375)⁶⁰] / [(1 + 0.00375)⁶⁰ - 1]

3. Calculate the numerator: 0.00375 × (1.00375)⁶⁰ ≈ 0.00375 × 1.287 ≈ 0.00478
4. Calculate the denominator: (1.00375)⁶⁰ - 1 ≈ 1.287 - 1 = 0.287
5. Divide numerator by denominator: 0.00478 ÷ 0.287 ≈ 0.0167
6. Multiply by principal: $25,000 × 0.0167 ≈ $417.50

Your monthly payment would be approximately $417.50. Over 60 months, you would pay a total of $25,020, with $200 in interest.

Interpreting Results

When you use this calculator, you'll see several key results:

• Monthly Payment: The amount you'll pay each month.
• Total Interest: The total amount of interest you'll pay over the life of the loan.
• Principal Repayment: The portion of each payment that goes toward paying off the principal.

Use this information to compare different loan options, understand your financial commitment, and plan your budget accordingly.