A lump sum gets more time in the market, but results still depend on your return assumptions. Compare conservative, mid, and optimistic scenarios.
Open the Money Growth Calculator| Return rate | Final balance | Amount invested |
|---|---|---|
| 5% (conservative) | ~$21,600 | $5,000 |
| 7% (mid) | ~$38,100 | $5,000 |
| 10% (optimistic) | ~$87,200 | $5,000 |
Investing $5,000 as a one-off lump sum for 30 years is one of the most compelling arguments for investing early and leaving it alone. At a 7% return your $5,000 grows to around $38,100 — more than seven times your original investment with zero additional contributions. At 10% the result is extraordinary — $87,200 from a single $5,000 investment, nearly 17 times what you put in. For a young Australian who invests a $5,000 tax return at age 30 and never touches it, this could be worth close to $90,000 by retirement at 60.
If you have the money ready now, investing earlier gives compounding more time. Waiting in cash can reduce long‑term growth (but may reduce short‑term risk).
If investing everything at once feels risky, model a smaller lump sum plus monthly contributions. You’ll see the tradeoff between time invested and timing risk.
Often lump sum wins mathematically because money is invested sooner, but behaviour and timing risk matter.
Try 5% (conservative), 7% (mid), 10% (optimistic) to see a range.
No. Treat results as estimates. You can lower the assumed return rate to be conservative.
If the timeline is short, a stable savings option may be safer. Consider using the ETF vs Savings comparison.
See /how-compound-interest-works.html.