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Calculate if I could save using an offset account

Play with this calculator to explore how much you could save on your home loan interest and term.


How does an offset account work? 

Normally, you accrue interest on your whole home loan balance. But when you link our everyday Westpac Choice account to our Rocket Repay home loan, it becomes an offset account. Every dollar there reduces your loan interest, while giving you easy access to it for day-to-day living, or a rainy day.

Everything offset


Our 100% offset account lets you balance saving with spending, while you’re paying off your home loan. Offset savings can depend on a few things, like your loan amount, your interest rate and how you’ll use your offset account. 

You can save in two ways: 

  1. Every dollar in your offset counts towards reducing the interest on your daily home loan interest, giving you immediate savings. When home loan interest rates are higher than savings account and term deposit interest rates, your interest saved would be higher than the interest you'd earn.  
  2. Paying less interest then reduces the amount of interest accrued on your interest (compounding interest) so you could pay your loan balance off faster.

That's a very good question, and depends on a few things like how you’ll use your account, your redraw facility, interest rate and loan amount. 

Advantages of our offset account:

  • Every single dollar of your balance works for you, e.g. your salary, spare funds and day-to-day living allowance (only pay interest on your loan balance minus your daily offset balance)
  • Set & forget – no need to transfer extra repayments into your home loan to reduce home loan interest  
  • Keep track of complex day-to-day finances 
  • Freedom & ease – quick access to money
  • Confidence – a safety buffer for a rainy day, without the need to redraw
  • Investor-friendly – option to use your offset account solely for your personal transactions, to prevent them from inadvertently mixing with your investment home loan expenses.


  • Home loans with offset tend to have higher rates and fees 
  • Large sums in a transaction offset account can be a spending temptation for some 
  • If your offset balance is always low (e.g. under $10,000), it may not be worth paying for this feature
  • You won’t earn any interest on your offset account
  • All of our Westpac variable rate home loans let you make unlimited extra repayments and redraws, with no redraw fee2. So it may be worth comparing our offset home loan to our basic Flexi First Option Home Loan, which has our lowest variable rate home loan and comes with lower fees.

Understand our offset account

Compare our loans

Choose a scenario below that describes you:


You can link this to your Rocket Repay Home Loan.

Westpac App: Search Home loan offset in the Smart Search bar

Online Banking: Go to Service > Services > Account services and select Home loan offset settings

First, you’ll need to open a new Choice transaction account in the same name (or names) as your Rocket Repay Home Loan, and link it to your home loan account. You can do this in Online Banking or the Westpac App. (If your home loan isn’t packaged there could be a $5 monthly fee1 – so you may want to close the first account). 

Westpac App: Search Home loan offset in the Smart Search bar

Online Banking: Go to Service > Services > Account services and select Home loan offset settings

First, you’ll need to open a Choice account in the same name (or names) as your home loan, then link it to your home loan account. You can do this in Online Banking or the Westpac App:

Westpac App: Search Home loan offset in the Smart Search bar

Online Banking: Go to Service > Services > Account services and select Home loan offset settings

Want a home loan with an offset account? You can apply online or request a call back. One of our home lending experts will be in touch.

Things you should know

Credit Criteria, fees and charges apply. Terms and conditions available on request. Based on Westpac's credit criteria, residential lending is not available for Non-Australian Resident borrowers.


++ This is an estimate of the potential offset savings based on the information provided: your actual savings may differ depending on your situation. Changes in interest rate will affect the calculation. Our lending criteria, and basis upon which we assess what you can afford, may also change at any time without notice.

The output or result of this calculator:

  • Is subject to the assumptions, which are subject to change. 
  • Is prepared without knowing your personal financial circumstances. Before you act on the output of the calculators, please consider if it’s right for you: we recommend that you consult your financial adviser before taking out a loan. If you need more info, please call 1300 786 029.  
  • Doesn’t represent either a quote, pre-qualification for a loan or an offer of credit.
  • Doesn’t include all applicable fees.
  • May not be taken into account if you apply for a loan with us, as we’ll make our own calculations. When assessing ability to service a loan, Westpac may use an interest rate that is higher than the current interest rate for the loan requested.


The interest rates used in the calculator:

  • Are current, as indicated on our home loan interest rate pages
  • Are Westpac's standard interest rates and include any package or promotional discounts
  • Are subject to change.


This mortgage offset calculator offers an estimate of the interest and time you could save by having money in your Westpac offset account, and is based on the info you’ve entered. 


Calculator assumptions 

  • Interest rate. This calculator doesn’t take into account compound interest savings. 
  • Interest and loan term savings. This calculator compares a home loan without an offset account, to a loan linked with an offset account. Total Interest Saved = (Total interest paid on loan without offset) - (Total interest paid on loan with offset). 
  • Extra repayments. Calculator is based on your offset account balance, and doesn’t take into account any extra mortgage repayments you might make to your home loan account. 
  • Weekly, fortnightly or monthly repayments. Your initial loan will be set up as monthly. Weekly and fortnightly repayments are only available with P&I. To calculate these, we multiply your P&I monthly amount by 12 to get a yearly value, then divide either by 26 for fortnightly or 52 for weekly, and round it up.  


*Comparison rate: The comparison rate is based on a loan of $150,000 over the term of 25 years. WARNING: This comparison rate is true only for the examples given and may not include all fees and charges. Different terms, fees or other loan amounts might result in a different comparison rate.

#Premier Advantage Package: Conditions of Use and $395 annual package fee applies. You must either hold or be approved for a Westpac Choice transaction account in order to qualify and continue to receive the benefits of the Premier Advantage Package. Applicants must have a Westpac Choice transaction account linked to the home loan at the time of settlement and must keep this account open for 60 days after settlement. Before deciding to acquire a Westpac Choice account, read the terms and conditions, and consider whether the product is right for you. Tax consequences may arise from this promotion for investors and customers should seek independent advice on any taxation matters.
Premier Advantage Package Conditions of Use (PDF 80KB)


1 Monthly $5 offset Westpac Choice account-keeping fee waivers:

  • The account’s linked to our packaged Rocket Repay Home Loan
  • You deposit at least $2,000 each month
  • You're under 21 years old, or a full-time tertiary student
  • You have an Australian Pensioner Concession Card or Health Care Card
  • You’re new to Australia, or an expatriate customer (for the first 12 months).


2 Redraw facility: if you have ‘available funds’ (you’re ahead on your home loan repayments) and you’ve activated your redraw facility, you’re free to redraw them with no redraw fee. Read our Redraw Authority form (PDF 66KB) for full details.