Long time horizons make compounding powerful. Run a few return-rate scenarios and compare the range of outcomes.
Try the Money Growth CalculatorOver 30 years, your time horizon often matters more than trying to find the “perfect” return. Compounding has decades to work.
| Return rate | Final balance | Total contributed |
|---|---|---|
| 5% (conservative) | ~$90,000 | $39,000 |
| 7% (mid) | ~$132,000 | $39,000 |
| 10% (optimistic) | ~$245,000 | $39,000 |
Investing $25 a week for 30 years means contributing $39,000 of your own money — yet at a 7% return, compounding adds around $93,000 on top, growing your balance to roughly $132,000. Thirty years is where the compounding curve really steepens — your money more than triples what you put in at mid-range returns, and at 10% it grows to $245,000. Starting with just $25 a week in your 30s could mean a meaningful retirement nest egg by your 60s.
If $25/week is your starting point, test “step-ups” by increasing the monthly contribution every few years. Even small increases can move the result a lot.
It can be. The key is consistency and time. Over 30 years, even small contributions can compound into meaningful totals.
Start conservative (5%), then compare with a mid-range assumption (7%) and an optimistic scenario (10%).
For long-term modelling, converting to a monthly number is usually close enough.
No. Fees and taxes reduce real outcomes. Treat results as estimates.
See /how-compound-interest-works.html for the simple explanation and formula.