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) | ~$165,000 | $52,000 |
| 7% (mid) | ~$284,000 | $52,000 |
| 10% (optimistic) | ~$685,000 | $52,000 |
Investing $25 a week for 40 years means contributing $52,000 of your own money — but at a 7% return, compounding adds an extraordinary $232,000 on top, growing your total to around $284,000. Forty years is where compounding becomes truly remarkable — at 10% your balance could reach $685,000 from just $25 a week. This is the ultimate argument for starting young: someone who begins at 25 and invests just $25 a week could retire at 65 with a substantial nest egg without ever increasing their contributions.
If you invest $25/week for 40 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.