Compounding is what happens when your investment returns start earning returns of their own. In the first few years the effect is small. Given enough time, it becomes the main driver of growth.
A simple example
Imagine investing $200 a month and earning an average of 6% a year, compounded monthly. These numbers are illustrative: real returns vary from year to year and aren’t guaranteed.
| Years investing | Total you put in | Approximate value |
|---|---|---|
| 10 | $24,000 | $32,800 |
| 20 | $48,000 | $92,400 |
| 30 | $72,000 | $200,900 |
After 30 years, contributions of $72,000 have grown to roughly $200,900. Most of that final balance is growth, and most of the growth arrives in the later years: going from year 20 to year 30 adds about $108,000, more than the entire balance after 20 years.
What this means in practice
- Start early, even small. Time does much of the heavy lifting, so a modest amount invested now can outgrow a larger amount invested later.
- Be consistent. Regular contributions, automated if possible, keep compounding working.
- Avoid interrupting it. Selling in a panic or withdrawing early resets the clock.
- Watch costs. Fees compound too, in the wrong direction. See our guide to investment fees.
Key takeaway
Compounding rewards patience. The earlier you start and the longer you stay invested, the more of the work your returns do for you.
This guide is for education only and isn’t personal financial advice. Investing involves risk, including the possible loss of money you invest. Example figures are illustrations, not predictions.