Run 3 return-rate scenarios to see a realistic range of outcomes — then adjust your monthly amount until it fits your budget.
Open the Money Growth Calculator| Return rate | Final balance | Total contributed |
|---|---|---|
| 5% (conservative) | ~$123,000 | $72,000 |
| 7% (mid) | ~$156,000 | $72,000 |
| 10% (optimistic) | ~$228,000 | $72,000 |
Investing $300 a month for 20 years means contributing $72,000 of your own money — and at a 7% return, compounding adds around $84,000 on top, growing your balance to roughly $156,000. Twenty years more than doubles your contributions, with compounding adding more than you put in yourself. For many Australian families, $300 a month is a realistic target that over two decades quietly builds a six-figure investment portfolio.
If $300/month feels hard right now, test a smaller starting amount and increase it each year. Even small step-ups can move the result a lot over long horizons.
It can be. The biggest drivers are consistency and time. Use the calculator to compare multiple return scenarios.
Try 5% (conservative), 7% (mid), and 10% (optimistic) to see a range.
No. Treat results as estimates. You can lower your assumed return rate to be conservative.
If you can’t do both, extra time often helps a lot. Then increase contributions over time.
See /how-compound-interest-works.html.