EuroCalc

Compound Interest Calculator

This compound interest calculator projects how an investment grows over time when interest compounds and you add regular contributions. Example: CHF 10,000 invested today plus CHF 300 monthly at 6% over 25 years grows to roughly CHF 250,000 — more than CHF 150,000 of which is pure interest.

Final value
CHF 253'587
Total contributed
CHF 100'000
Interest earned
CHF 153'587
Growth over time
Contributions · CHF 100'000
Interest · CHF 153'587

How to use this calculator

  1. 01Enter the amount you start with today.
  2. 02Add a recurring monthly contribution if relevant.
  3. 03Set a realistic expected annual return (long-term equity averages 6–8%).
  4. 04Choose the time horizon — compounding rewards patience.
Key takeaways
  • Compounding means earning interest on interest — growth accelerates over time.
  • Time matters more than rate: doubling the horizon often beats doubling the return.
  • Regular contributions smooth out market timing and dramatically increase the final value.
  • Higher compounding frequency (monthly vs annual) makes a small but noticeable difference.