Compound Interest Calculator
Calculate how your investment can grow over time.
Enter your starting capital, monthly contribution, investment period and expected return — the calculator shows how your wealth grows through compound interest and breaks down how much comes from your own contributions versus interest earned.
Compound Interest Calculator
Calculate how your investment can grow over time.
1–60
0–30%
Calculate to see results
Adjust the values and click “Calculate”.
Why does compound interest matter so much?
With compound interest, returns are calculated not only on your original capital but also on previously earned interest. Over long periods, this creates exponential growth. For example, saving €200 per month at 5% annual return yields around €162,000 after 30 years — yet only €72,000 was contributed directly. The remaining €90,000 is generated purely by compound interest. The earlier you start, the more powerful this effect becomes. For retirement planning — whether via an ETF savings plan, unit-linked pension or Rürup pension — compound interest is the central principle.
Who is this calculator for?
This calculator is most useful for those starting their careers who want to begin building wealth early, self-employed professionals and freelancers without statutory pension coverage who are planning private retirement provision, and anyone comparing scenarios across different savings rates, returns and time horizons.