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Compound interest calculator (CHF)
See how a start amount and a monthly saving grow over the years, and how much of the end value is growth on top of your deposits.
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Fill in your numbers and calculate. We do not store your inputs and no email is required.
Educational model, not financial advice and not a forecast.
How compound interest works
Interest on interest: the mechanism
Compound interest means your money earns a return, and that return then earns a return itself. In the first year, CHF 10'000 at an assumed 5% grows by CHF 500. In the second year the 5% applies to CHF 10'500, so the gain is CHF 525, and so on: each year's growth becomes part of the next year's base. Over 20 years the same CHF 10'000 grows to about CHF 26'533, more than two and a half times the start, without a single additional deposit.
- End value = start amount × (1 + return) to the power of the years.
- This calculator credits your monthly savings at the end of each year and compounds once per year; results are shown before taxes and fees.
Time is the biggest lever
The curve is flat at first and steep at the end. Saving CHF 500 per month at an assumed 5% grows to roughly CHF 198'000 after 20 years, but to roughly CHF 399'000 after 30 years: the last ten years add more than the first twenty, because by then the return works on a large base. Starting early therefore counts for more than starting big.
Compound interest is also the engine of financial independence. Your FIRE number is reached exactly when this compounding has carried your wealth to the point where a sustainable withdrawal covers your spending. The FIRE calculator linked below builds directly on the mechanic you see here.
What return is realistic in Switzerland?
The return field is pre-filled with a long-term diversified-portfolio assumption from our parameter set, and you can change it freely. For orientation: long-run studies such as the UBS Global Investment Returns Yearbook, which tracks Swiss markets back to 1900, put the very long-term nominal return of broadly diversified equities in the mid single digits per year, with bonds and savings accounts well below that. Those are historical averages over very long periods, not a promise for the years ahead, and any single decade can look very different. A projection with a constant rate also smooths out swings that in reality can be severe.