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Compound growth means your return earns a return of its own. Over twenty or thirty years, most of your wealth stops coming from you and starts coming from the market. To see where you stand before you start, look at average wealth in Switzerland: median CHF 34,598, mean CHF 441,249. This calculator shows how large that market-driven part gets in your case, and how much fees take out of it. Remember: the calculator shows you the what. The book shows you the how.
In today’s purchasing power: CHF 0
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| Year | Paid in | Compound growth | Capital | In today’s money |
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How this is calculated
The calculator compounds monthly. The annual rate is divided by twelve, your contribution lands at the end of the month, and from the next month it earns a return of its own. The formula behind it is:
Final capital = Starting capital × (1 + i)n + Contribution × [((1 + i)n − 1) ÷ i]
i is the monthly rate, meaning the annual return less costs, divided by twelve. n is the number of months. Costs come off the return directly, because that is exactly how they work: they do not reduce your balance, they reduce your growth.
Our own calculation using the tool on this page, monthly compounding, as at August 2026. Return and costs are assumptions, not promises.
The one thing to remember: time beats amount. Starting ten years earlier does more, in the default calculation above, than doubling the monthly contribution. You can negotiate how much you save. You cannot negotiate how long you have.
Why 7% is the default
7% is the long-run average of broad equity markets before costs, measured over decades rather than single years. In practice you will never see seven percent in a year. You will see plus twenty, then minus fifteen, then plus nine. The average only appears at the end.
If you want a more cautious number, set the slider to 5%. If you think in francs and worry about currency swings, use 5% and read our guide to investing in Switzerland alongside it. A savings account currently pays well below inflation, which is why the calculator has an inflation field: it shows what your final capital is worth in today’s purchasing power.
What this calculator is not. It is arithmetic, not a forecast. It does not know your taxes, a market fall at the wrong moment, or a redundancy in year twelve. Equity markets drop, sometimes for years. A result of CHF 432,000 does not mean you will receive CHF 432,000. It means the compounding effect is that large if the assumptions hold.
Four rules that make the difference
- Start before you feel ready
The most expensive mistake is not the wrong investment. It is the three years you spent researching and doing nothing. - Automate the contribution
A standing order on payday beats any good intention. What you transfer at the end of the month is what you eventually stop transferring. - Count costs in francs, not percent
1.5% instead of 0.4% sounds like nothing. Enter both in the calculator and look at the difference in the final capital. - Leave it alone
Compounding happens in the last ten years, not the first. Anyone who gets out in year fifteen never sees most of the effect.
Compounding inside pillar 3a
The same effect decides your pillar 3a, and more sharply than anywhere else. Leave the balance in a cash account and you get almost no compounding, because the interest rate is close to zero. Invest it and you get thirty or forty years of it. Set the calculator to 0.25% and then to 7%, and you see the difference in francs.
The second pillar runs the same maths, just hidden: your pension certificate usually projects at the minimum rate of 1.25%, while well-run funds credit noticeably more. What that adds up to over the years, and how to read your certificate, is in the conversion rate comparison for 2026.
Which provider charges what in fees is in our pillar 3a comparison. For a taxable account outside pillar 3a, use the trading platform comparison.
Common questions
What is compound interest, in plain terms?
You earn a return on your money. Next year you earn a return on your money and on last year’s return. The longer that runs, the larger the part grows that you did not pay in yourself.
What return should I assume?
7% is the usual long-run average of broad equity markets before costs. 5% is the more cautious assumption. For a Swiss savings account the realistic figure is currently well under one percent.
Does the calculator compound monthly or yearly?
Monthly. The annual rate is divided by twelve and your contribution lands at the end of each month. That matches how a standing order actually works.
Why are costs taken off the return rather than the balance?
Because custody fees and fund costs work exactly that way. They take a slice of your growth every year. Over thirty years, one percent more in fees costs a far larger share of the final capital than the single percent suggests.
How much do I need to save a month to reach a million?
Set your time horizon in the calculator and move the monthly contribution until the final capital reads one million. At 7% return, 0.4% costs and 30 years, the figure is around CHF 890 a month with no starting capital.
Does the calculator account for tax?
No. Wealth tax, withholding tax and the tax on a pillar 3a withdrawal depend on your canton and your situation. The calculator shows the pure compounding maths.
Basis of calculation: monthly compounding, annual rate divided by twelve, contribution at month end, costs deducted from the return. The 7% return assumption is the long-run average of broad equity markets before costs. All figures are arithmetic based on your inputs and are not a forecast. Last checked: August 2026.
The calculator shows you the what. The book shows you the how.
The Swiss Investing Playbook takes you in 90 days from a salary account to a portfolio you understand. Free, and it stays free. Day 1 takes five minutes. Get the book.
