24 Jun, 2024
Uncategorized Comments Off on How Is Your Home Loan Interest Calculated?

Effectively managing your home loan finances requires a clear understanding of how interest is calculated by Australian lenders. This knowledge can significantly impact your repayment strategy and potential cost savings over the life of the loan.

Interest Fundamentals

When obtaining a home loan in Australia, borrowers are responsible for repaying not only the principal amount borrowed but also the interest charged by the lender. Interest is the cost of borrowing money, expressed as a percentage of the loan balance known as the annual percentage rate (APR) or per annum (p.a.) rate.

Simple Interest Calculation Method

Australian lenders use the simple interest method to calculate home loan interest charges. This method involves dividing the annual interest rate by the number of days in the year to determine the daily interest charge, which is then multiplied by the outstanding loan balance.

For example, if you have a $600,000 home loan with a 6.5% p.a. interest rate, your daily interest charge would be approximately $105.48 (based on a 30-day month). Consequently, your monthly interest repayment would total around $3,164.40.

Interest Accrual and Billing

Interest on Australian home loans typically accrues daily based on the outstanding loan balance but is billed monthly. Each day, interest accumulates on the remaining amount owed, and at the end of the month, the total accrued interest for that period is charged.

Repayment Breakdown

Unless you have an interest-only loan, your monthly repayment will contribute towards both the principal amount and the interest. The exact breakdown of your repayment can be complex and may involve additional fees and charges, so consulting with your lender for clarity is recommended.

Long-term Interest Impact

Over the course of a typical 20 to 30-year loan term, interest payments can accumulate significantly. While home loan interest rates are generally lower than other forms of borrowing, such as credit cards or car loans, the total interest paid over the years can be substantial.

For instance, on a $600,000 mortgage over 25 years at a 6.5% interest rate, the total interest paid using the simple interest method would be approximately $752,321. This substantial amount highlights the importance of implementing strategies to minimize interest costs.

Additional Factors Impacting Home Loan Interest

Loan Amount and Term

The amount borrowed and the loan term can significantly influence the total interest paid. Generally, larger loan amounts and longer loan terms result in higher overall interest costs. However, some lenders may offer discounted interest rates for larger loan amounts.

Repayment Frequency

The frequency of your repayments can also affect the interest charged. In most cases, more frequent repayments (e.g., weekly or fortnightly) can result in lower interest costs compared to monthly repayments. This is because more frequent payments reduce the outstanding balance faster, thereby reducing the interest accrued over time.


The size of your down payment can impact the interest rate offered by lenders. Typically, larger down payments of 20% or more may qualify you for lower interest rates, as lenders perceive a lower risk with a higher initial investment.

Top Tips to Reduce Interest Costs

Negotiate a Lower Interest Rate: Ask us to approach your lender and inquire about the possibility of reducing your interest rate. If you have a good repayment history and a solid credit score, you may have leverage to negotiate a better deal.

Review your home loan at least annually – Almost all lenders save the biggest discounts on interest rates for new clients.  Once you have been with a lender for sometime your home loan interest rate may no longer be competitive.  Your Brisbane Home Loans team will review your home loan annually to make sure it is still working for you – we can request a discount and if the rate is still not competitive, we can seek out better deals.  (Note: Because the Australian property market has been on an upward trajectory, even a couple of years after purchasing, the value of your home has likely grown substantially, this can mean that your loan to value ratio has dropped, meaning you qualify for a lower interest rate)

Consider Refinancing: Explore refinancing options periodically. Refinancing ensures that your home loan aligns with your current financial situation and presents an opportunity to secure a lower interest rate.

Utilize Offset Accounts: Offset accounts are a strategic tool for reducing interest payments. By linking a savings account to your home loan, the funds in the offset account offset the interest charged on your loan balance, leading to substantial savings over time.

Pay your Repayments more often:  By paying weekly or fortnightly your balance is reduce more often, therefore meaning that less interest is payable.

By understanding how interest is calculated on your home loan and implementing smart financial strategies, you can potentially save thousands of dollars in interest payments over the life of your loan. Proactively exploring your options and taking control of your financial future is crucial for optimizing your home loan repayments. Brisbane Home Loans is your local expert, ready to assist you with your loans, structure and how to get the right deal for you.  Give us a call today. 07) 3889 9250