Use conservative, mid, and optimistic return assumptions to see a realistic range of outcomes — then decide what’s feasible for your budget.
Open the Money Growth Calculator| Return rate | Final balance | Total contributed |
|---|---|---|
| 5% (conservative) | ~$134,000 | $78,000 |
| 7% (mid) | ~$169,000 | $78,000 |
| 10% (optimistic) | ~$247,000 | $78,000 |
Investing $75 a week for 20 years means contributing $78,000 of your own money — and at a 7% return, compounding adds around $91,000 on top, growing your balance to roughly $169,000. That's more than double your contributions, with compounding doing as much work as you did. At $75 a week — roughly the cost of a couple of restaurant meals — this is an achievable target for many working Australians that could build a serious financial buffer over two decades.
If you invest $75/week for 20 years, the result depends heavily on the return rate. Use the calculator to test a conservative, mid, and optimistic scenario.
It’s a solid starting habit. The best amount is one you can maintain consistently, then increase over time.
Use 5% for a conservative baseline, 7% for a mid-range estimate, and 10% as an optimistic scenario.
No. Treat results as estimates. You can lower your assumed return rate to be more conservative.
For long-term modelling, converting to monthly is usually close enough.
See the simple explanation on /how-compound-interest-works.html.