Why does time count for more than the amount?
Two people pay in the same amount every month. Person A starts earlier than Person B, and both stop at the same age.
Person A pays in more, because the paying goes on for longer, and ends up clearly ahead of Person B. The difference does not come from the amount but from the years in which the first payments are already earning.
Starting earlier does more than paying in more later.
US$46,000 paid in over 15 years, at 14.7 % a year, comes to US$198,349. Of that, US$152,349 was never paid in.
15 years · 14.7 % per year · Initial investment US$10,000 · Monthly contribution US$200
Questions people ask
What is compound interest?
Interest that earns interest of its own. After the first year it is no longer only the deposit that grows, but also what the deposit has brought in so far.
Why do early years weigh more than late ones?
Because every year builds on the result of all the years before it. An amount that lies ten years longer is multiplied by the same factor ten more times.
Is compound interest a guarantee?
No. The sum holds for an assumed return. Whether an investment delivers that return is not something the sum says.
Source: Annual values of the comparison series, as of 2025, retrieved 2026-11-09
Two people with the same monthly amount, one starts earlier.
The simulation, the comparison and the Beam stay free.
Education, not advice. Disclaimer