The Compound interest Interest paid on the initial principal and the accumulated interest on money borrowed or invested.

 calculator helps you work out:

  • what money you’ll have if you save a regular amount
  • how compounding increases your savings interest
  • the difference between saving now and saving later
  • how to calculate compound interest


  • 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 changing interest rates.
  • This calculator is not intended to be your sole source of information when making a financial decision. Consider whether to get advice from a licensed financial adviser.


  • 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 set).
  • 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.

FAQs — frequently asked questions

FAQs – frequently asked questions

Q. How does compound interest work?

A. See compound interest to find out more.

Q. Are the results of the compound interest calculator shown in today’s dollars?

A. The results of this calculator are shown in future dollars. No adjustment has been made for inflation.

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 is no longer available.