Auto Loan Calculator with Existing Loan

When you have an existing auto loan and want to refinance or consolidate, this calculator helps you determine your new loan terms. By comparing your current loan with potential new loan options, you can make an informed decision about whether refinancing is beneficial.

How This Calculator Works

This auto loan calculator with existing loan compares your current loan with a new loan scenario. You input your current loan details and potential new loan terms, then the calculator shows you the differences in monthly payments, total interest paid, and payoff time.

Note: This calculator assumes you'll pay off your existing loan before taking on the new loan. If you plan to pay both loans simultaneously, the results may differ.

Key Features

Compare monthly payments between your current and new loan
Calculate total interest paid over the life of both loans
Determine how much sooner you'll pay off your loan with the new terms
Visualize the payment difference with a chart

When to Use This Calculator

This tool is useful when you're considering:

Refinancing your auto loan to get a lower interest rate
Consolidating multiple auto loans into one
Switching from an interest-only loan to a principal-and-interest loan
Evaluating different loan term lengths

Formula Used

The calculator uses standard loan payment formulas to calculate both your current and new loan payments.

Monthly Payment Formula:

P = L × (r(1 + r)^n) / ((1 + r)^n - 1)

Where:

P = Monthly payment
L = Loan amount
r = Monthly interest rate (annual rate ÷ 12 ÷ 100)
n = Number of payments (loan term in years × 12)

The calculator then compares these values to show the difference between your current and new loan payments.

Assumptions

All interest rates are annual percentage rates (APR)
Loan terms are in whole months
No additional fees or closing costs are included
Payments are made on time each month

Worked Example

Let's say you have a current auto loan with these terms:

Loan amount: $20,000
Interest rate: 8% APR
Loan term: 48 months

And you're considering a new loan with these terms:

Loan amount: $20,000
Interest rate: 5% APR
Loan term: 60 months

Using the calculator, you would find:

Current monthly payment: $441.86
New monthly payment: $358.24
Payment difference: $83.62 per month
Total interest paid with current loan: $1,607.20
Total interest paid with new loan: $1,000.00
Interest savings: $607.20
Payoff time difference: 12 months sooner

This example shows that refinancing to the new loan terms would save you $607.20 in interest and pay off your loan 12 months earlier.

Frequently Asked Questions

How accurate is this auto loan calculator?

This calculator provides estimates based on the formulas and assumptions shown on the page. For precise financial advice, consult with a loan professional or financial advisor.

Does this calculator account for fees and closing costs?

No, this calculator focuses on the loan terms and payments. Additional fees and closing costs would need to be considered separately when making a refinancing decision.

Can I use this calculator for personal loans or other types of loans?

This calculator is specifically designed for auto loans. While the formulas are similar, the terms and conditions of personal loans may differ significantly.

What if I want to keep making payments on my current loan while taking out a new one?

The calculator assumes you'll pay off your current loan before taking on the new one. If you plan to pay both loans simultaneously, the results may differ and you should consult with a financial advisor.