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.
↗ Read the in-depth guide
Compound Interest Explained: The Math Behind Long-Term Wealth
How compounding really works, why time matters more than rate, and how to use it for retirement, savings and investment planning.
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How to use this calculator
- 01Enter the amount you start with today.
- 02Add a recurring monthly contribution if relevant.
- 03Set a realistic expected annual return (long-term equity averages 6–8%).
- 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.
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