Compound interest calculator

Estimated time: 5 mins

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This calculator helps you work out:

  • What money you'll have if you save a regular amount
  • How compounding increases your savings
  • The difference between saving now and saving later

About this calculator - disclaimer & assumptions


  • A model not a prediction. Results are only estimates, the actual amounts may be higher or lower. We cannot predict things that will affect your decision such as movements in interest rates.
  • This calculator is not intended to be your sole source of information when making a financial decision. You should consider whether you should get advice from a licensed financial adviser.
  • Refer to the "How compound interest works" section at the bottom of the calculator for more detail.


  • Initial deposit is made today
  • Regular deposits are made at the end of year, month, fortnight, week, or day (according to the deposit frequency you nominated)
  • Interest is credited either monthly or annually, in line with standard industry practice
  • The delayed start comparison feature will have the same regular deposit frequency

Compound interest calculator FAQs - frequently asked questions

Q: Why have you changed the calculator?

A: We upgrade our calculators regularly due to technological advances, regulatory changes and customer feedback. Once a calculator has been upgraded, the old version will no longer be available.

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Last updated: 02 Feb 2016