Compound Interest Calculator Australia

See how a starting balance and regular contributions grow over time. Pop in your numbers to project the future value, what you actually put in, and how much of the total is pure compounding.

The balance you are beginning with today. Leave at zero if you are starting from scratch.
$
How much you add each period, on top of the starting amount. Set the period below.
$
Contributions are added at the end of each period, and interest compounds at the same frequency.
The yearly return you expect, before tax and fees. We convert it to your chosen period.
%
How long the money stays invested and keeps compounding.
yrs
Optional. Apply your tax rate to the interest each year for a simple after-tax view. Leave blank to ignore tax.
%
Projected future value
$0
  • Starting amount$0
  • Total contributions$0
  • Total you put in$0

Enter a starting amount or contribution, a rate and a number of years to see your projection.

Building wealth inside a company, trust or SMSF? We will structure it so more of this growth stays yours.

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General information only, current for the 2025-26 financial year. This is a simplified projection that assumes a constant return and constant contributions, and it ignores inflation, fees, variable markets and the detail of how investment earnings are taxed in your situation. It is not personal financial or tax advice. For a plan built around your goals, talk to us.

What This Calculator Assumes

What is compound interest?

Compounding is earning a return on your returns. Each period, interest is added to your balance, and the next period earns interest on that larger balance. Over long horizons it is the difference between steady saving and real wealth, because the growth itself starts generating growth.

How are contributions and compounding handled?

We add your regular contribution at the end of each period and compound interest at the same frequency you choose (monthly, fortnightly, quarterly or yearly). The annual rate is divided across the periods in a year, so a 6% annual rate becomes roughly 0.5% per month. Real accounts may credit interest on different terms, so treat this as an estimate.

Does this account for tax and inflation?

Only if you ask it to. The optional marginal tax rate field applies your rate to the interest each year for a simple after-tax figure. The projection does not adjust for inflation, so the future value is in today's dollars before the cost of living is factored in. How earnings are actually taxed depends on the structure they sit in (your own name, a company, a trust or super), which is exactly where good advice pays for itself.

Turn A Projection Into A Plan

A spreadsheet shows the maths. We help you build the structure around it, so your business and personal wealth grow together and the tax stays efficient.

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