Home Loan Repayment Calculator with Offset Account

This home loan repayment calculator helps you estimate your monthly payments when you have an offset account. An offset account is a savings account linked to your home loan, where the balance reduces your loan amount and interest charges.

How the Calculator Works

The calculator determines your monthly loan repayment by considering your loan principal, interest rate, loan term, and the balance in your offset account. The offset account balance reduces your loan amount, which in turn reduces the interest you pay.

Key Formula

The effective loan amount is calculated as: Effective Loan Amount = Principal - Offset Balance

Monthly repayment is then calculated using the standard loan repayment formula: Monthly Repayment = P * (r(1+r)^n) / ((1+r)^n - 1) where P is the effective loan amount, r is the monthly interest rate, and n is the number of payments.

This calculation helps you understand how much your offset account can save you in interest payments over the life of your loan.

How to Use This Calculator

Enter your loan principal amount (the total amount you borrowed).
Enter your current interest rate (annual percentage rate).
Enter the term of your loan in years.
Enter your current offset account balance.
Click "Calculate" to see your estimated monthly repayment.
Review the results and chart showing your loan balance over time.

Important Notes

This calculator provides an estimate. Actual repayments may vary.
The offset account balance is assumed to remain constant throughout the loan term.
Interest rates and loan terms can change over time.

Formula Explained

The calculator uses the following steps to determine your monthly repayment:

Calculate the effective loan amount by subtracting the offset account balance from the principal.
Convert the annual interest rate to a monthly rate by dividing by 12.
Convert the loan term in years to the total number of monthly payments by multiplying by 12.
Use the standard loan repayment formula to calculate the monthly payment.

The formula accounts for the reduced principal due to the offset account, which can significantly lower your interest payments over time.

Worked Example

Let's calculate a monthly repayment for a $300,000 loan with a 4% interest rate over 30 years, with an offset account balance of $50,000.

Effective loan amount: $300,000 - $50,000 = $250,000
Monthly interest rate: 4% ÷ 12 = 0.333%
Total payments: 30 years × 12 = 360 payments
Monthly repayment: $250,000 × (0.333% × (1 + 0.333%)^360) / ((1 + 0.333%)^360 - 1) ≈ $1,012.50

Without the offset account, the monthly repayment would be approximately $1,345. This example shows how an offset account can significantly reduce your monthly payments.

Frequently Asked Questions

How does an offset account affect my loan repayments?

An offset account reduces your loan amount by the account balance, which lowers the interest you pay. This can significantly reduce your monthly repayments.

Can I withdraw money from my offset account without affecting my loan?

Yes, you can withdraw money from your offset account without affecting your loan balance. The offset only applies to the current balance.

Is there a fee for maintaining an offset account?

Some banks charge fees for offset accounts, while others offer them for free. Check with your bank for specific details.

How does an offset account compare to a redraw facility?

An offset account reduces your loan balance, while a redraw facility allows you to borrow against your savings. Both can help manage your loan repayments, but they work differently.