Here's a number that might change how you think about money: CHF 10,000 invested today at 5% annual returns becomes CHF 43,219 in 30 years. Without adding a single franc. That's the compound interest effect doing the heavy lifting while you sleep.
This compound interest calculator lets you calculate compound interest in seconds: enter your starting capital, monthly contributions, rate and time, and you get your final amount in CHF. But here's what most calculators won't tell you: the real question isn't just "how much will I have?" but "will it be enough?" That's why our Financial Independence indicator also shows whether you'll actually get where you want to go.
How to Use This Compound Interest Calculator
This is your initial capital. Maybe it's CHF 5,000 you've saved, an inheritance, or your current savings account balance. If you're starting from zero, that's fine too.
How much can you realistically put in each month? Be honest with yourself. CHF 100/month is better than CHF 500/month that you'll abandon after three months. Consistency beats intensity.
This is where people get tripped up. Here are realistic benchmarks for Switzerland:
- Swiss savings accounts: 0.10% median today, the best account in our comparison pays 1.00%
- Pillar 3a savings accounts: 0.25% median, 1.00% at best
- Pillar 3a investment solutions: 3% to 7% (historical, long-term)
- Global stock market: 6% to 8% (historical, long-term)
How long until you need this money? For retirement planning, think 20 to 40 years. For a house down payment, maybe 5 to 10 years. The calculator shows your final amount, your total contributions and the interest earned, year by year.
What is Compound Interest? Simple vs. Compound Interest
Compound interest is when your money earns interest, and then that interest earns interest too. It's essentially your money making money, which then makes more money. The longer the time, the stronger the effect.
The difference from simple interest:
- Simple interest: You earn 5% on CHF 10,000 = CHF 500/year, forever
- Compound interest: Year 1 you earn CHF 500, Year 2 you earn 5% on CHF 10,500 = CHF 525, and so on
Compound Interest Formula: How to Calculate Compound Interest Yourself
You don't need to do this by hand, that's what the calculator is for. But once you understand the compound interest formula, you'll see right away why time and rate matter far more than the amount.
Without contributions (starting capital only): A = P × (1 + r)^n
P is your starting capital, r the interest rate (5% = 0.05), n the number of years and A the final amount. Example: CHF 10,000 × 1.05^10 = CHF 16,289 after 10 years. With simple interest you'd have only CHF 15,000.
With contributions (yearly contribution C at year end): A = P × (1 + r)^n + C × ((1 + r)^n − 1) / r
Example: CHF 10,000 to start plus CHF 1,200 a year at 5% for 20 years gives CHF 26,533 + CHF 39,679 = CHF 66,212. Our calculator compounds monthly (r/12 and n × 12 periods), which is why it shows CHF 68,230 for the same inputs.
The Rule of 72: divide 72 by the interest rate in percent and you get roughly the number of years it takes to double your money. At 8% that's 9 years, at 5% about 14 years, at 1% about 70 years. It's an approximation, not an exact result.
Swiss Interest Rates Today: Benchmarks for Your Calculation
Let's be realistic about returns in Switzerland. The account rates below come live from our comparison of savings interest rates and 3a accounts, the investment returns are historical ranges:
| Investment Type | Rate / Return | Basis | Risk Level |
|---|---|---|---|
| Savings account (median) | 0.10% | current rate | Very low |
| Best savings account | 1.00% | current rate | Very low |
| Pillar 3a savings account (median) | 0.25% | current rate | Very low |
| Best Pillar 3a savings account | 1.00% | current rate | Very low |
| Pillar 3a investment funds | 3% - 7% | historical | Medium |
| Swiss bonds | 1% - 3% | historical | Low |
| Global ETF portfolio | 5% - 8% | historical | Medium-high |
| Pure equity portfolio | 6% - 10% | historical | High |
The Financial Independence Indicator
Most compound interest calculators stop at "here's your future balance." Ours goes further.
The Financial Independence Indicator answers a more useful question: when could your investments generate enough passive income to cover your living costs?
Here's how it works:
- Enter your annual living costs (what you spend per year)
- Set a safe withdrawal rate (typically 3% to 4%)
- Add your current age
The calculator then shows you:
- How many years until your portfolio could sustain your lifestyle
- What age you'd reach financial independence
- Your estimated monthly passive income at the end
I added this feature because it's the question I kept asking myself. "CHF 500,000 sounds great, but what does it actually mean for my life?" The answer depends entirely on your spending. For someone spending CHF 40,000/year, that's 12+ years of runway. For someone at CHF 100,000/year, it's barely 5.
What's a Safe Withdrawal Rate?
The "safe withdrawal rate" (SWR) is the percentage you can withdraw annually without running out of money. The famous Trinity Study from 1998 suggested 4% works for 30-year retirements.
More conservative planners use 3% to 3.5%, especially for:
- Early retirees (longer time horizons)
- People in Switzerland (higher cost of living)
- Those who want extra buffer
Pro tip: A 4% withdrawal rate means you need 25x your annual expenses. At 3%, you need 33x. That's the math behind "the number" everyone talks about.
Compound Interest for Swiss Pillar 3a
The Pillar 3a is one of the best vehicles for compound growth in Switzerland. Here's why:
Tax deduction on contributions With a pension fund, you can deduct up to CHF 7,258 in 2026 from your taxable income. At a 30% marginal rate, that's CHF 2,177 in immediate tax savings. From 1 January 2027 the maximum rises to CHF 7,373 (CHF 36,864 without a pension fund), as the Federal Council decided (press release in German).
Tax-free growth No wealth tax and no income tax on interest and dividends while the money compounds. This is huge over 30+ years.
Forced long-term thinking You can withdraw the money at the earliest five years before the AHV reference age, so at 60 for men (with some exceptions). This prevents the biggest enemy of compound growth: yourself pulling money out early.
Pillar 3a: Savings Account vs. Investment Solution
Here's the uncomfortable truth: even the best Pillar 3a savings account pays 1.00% today, and the median is 0.25%. That barely keeps up with inflation.
Run the numbers yourself, with the maximum of CHF 7,258 a year for 30 years:
- at 1% = ~CHF 252,000
- at 5% = ~CHF 482,000
That's about CHF 230,000 difference. The tax deduction is the same either way. The only variable is whether you let your money actually work.
Compound Interest with an ETF Savings Plan, Savings Account or 3a: Which Pays More?
The same CHF 500 a month for 20 years, CHF 120,000 paid in total. The only difference is where the money sits:
| Option | Rate / Return | Final Amount | of which Interest |
|---|---|---|---|
| Savings account (median) | 0.10% | CHF 121,203 | CHF 1,203 |
| Best savings account | 1.00% | CHF 132,781 | CHF 12,781 |
| Best Pillar 3a savings account | 1.00% | CHF 132,781 | CHF 12,781 |
| ETF savings plan or 3a fund (assumption) | 5% | CHF 205,517 | CHF 85,517 |
The account rates are the current rates in our comparison, the 5% for the ETF plan is an assumption after costs, not a guarantee. To see what ETFs really earn after fees, use our ETF calculator.
Pillar 3a has a bonus the table doesn't show: at a 30% marginal rate, you also save about CHF 1,800 in tax a year on CHF 6,000 of contributions. You'll find the cheapest provider in our Pillar 3a comparison. And if you only want to compare bank rates, our savings calculator is the better tool.
Real Examples with Swiss Numbers
Example 1: The Early Starter
Profile: 25 years old, starting with CHF 5,000, investing CHF 300/month until age 65 (paid in: CHF 149,000)
| Scenario | Return | Final Value | Interest Earned |
|---|---|---|---|
| Savings account | 1% | CHF 184,000 | CHF 35,000 |
| Pillar 3a fund | 5% | CHF 495,000 | CHF 346,000 |
| Equity portfolio | 7% | CHF 869,000 | CHF 720,000 |
The difference between 1% and 7% over 40 years? CHF 685,000. That's not a typo.
Example 2: The Late Starter
Profile: 45 years old, starting with CHF 50,000, investing CHF 1,000/month until age 65 (paid in: CHF 290,000)
| Scenario | Return | Final Value | Interest Earned |
|---|---|---|---|
| Savings account | 1% | CHF 327,000 | CHF 37,000 |
| Pillar 3a fund | 5% | CHF 547,000 | CHF 257,000 |
| Equity portfolio | 7% | CHF 723,000 | CHF 433,000 |
At 5%, the 45-year-old even ends up higher than the 25-year-old (CHF 547,000 vs. CHF 495,000), but pays in almost twice as much out of pocket. The interest is far bigger for the early starter: CHF 346,000 against CHF 257,000. Time beats money, but starting capital helps you catch up on lost years.
Example 3: Financial Independence Target
Profile: 35 years old, CHF 60,000 annual expenses, 4% withdrawal rate, CHF 20,000 starting, CHF 2,000/month
Target portfolio needed: CHF 1,500,000 (60,000 × 25)
At 6% returns: just over 25 years to reach target (age 60)
That's the math behind early retirement in Switzerland: five years before the reference age, no lottery win required. Aggressive? Yes. Impossible? No.
Common Mistakes That Kill Compound Growth
Time in the market beats timing the market. Every year you delay costs you more than any market dip will.
A 1.5% annual fee vs. a 0.3% fee seems small. On CHF 100,000 at a 5% gross return over 30 years, that's about CHF 116,000 less in your final amount. Read that again.
Selling when markets drop locks in losses and destroys the compound effect. The money you pull out can never compound again.
Projecting 12% annual returns will leave you disappointed and possibly short of your goals. Use 5% to 7% for equity-heavy portfolios.
Compound Interest vs. Inflation
Here's the thing nobody wants to talk about: inflation eats your returns.
If you earn 5% but inflation is 2%, your real return is only 3%. Switzerland has historically had low inflation (averaging around 1% over the past decade), but 2022-2023 reminded us that can change quickly.
What this means for your calculations:
- A "safe" savings account at 1% with 2% inflation = losing purchasing power
- You need returns above inflation just to stay even
- This is why keeping large amounts in cash long-term is actually risky
The Swiss National Bank targets inflation around 0-2%. Factor this into your planning. If you're projecting 5% nominal returns, your real return might be 3-4%.
Monthly vs. Yearly Compounding: Does It Matter?
Short answer: not as much as you think.
CHF 10,000 at 5% for 10 years:
- Annual compounding: CHF 16,289
- Monthly compounding: CHF 16,470
- Daily compounding: CHF 16,487
The difference between annual and daily is CHF 198 over a decade. Focus your energy on the interest rate and your contribution amount instead. Those move the needle far more.
Frequently Asked Questions about Compound Interest
How long does it take for CHF 10,000 to double at 8%?
About 9 years. By the Rule of 72, divide 72 by the rate: at 8% your CHF 10,000 becomes CHF 20,000 in roughly 9 years, at 5% in about 14 years, and at 1% only after about 70 years. The rule is an approximation of compound interest. The calculator above shows the exact year.
How much is 5% compound interest over 10 years?
CHF 10,000 grows to CHF 16,289 in 10 years at 5% with annual compounding, 62.9% more. With simple interest you'd have only CHF 15,000, so the extra CHF 1,289 is pure compound interest. With monthly compounding you get CHF 16,470.
How many years will CHF 100,000 take to earn CHF 50,000?
At 5% it takes about 8.3 years, at 3% about 13.7 years, and at 1% more than 40 years (annual compounding, no further contributions). To calculate compound interest for your case, enter CHF 100,000 as starting capital and see in which year the final amount passes CHF 150,000.
How much interest do Swiss banks pay?
Not much. A Swiss savings account pays 0.10% median today, the best account in our comparison 1.00%. Pillar 3a savings accounts sit at 0.25% median and 1.00% at best. You'll find every rate in our overview of current savings interest rates.
What's the difference between simple and compound interest?
Simple interest is paid only on your capital, compound interest also on interest already credited. CHF 10,000 at 5% gives CHF 15,000 after 10 years with simple interest and CHF 16,289 with compound interest. For investments you'd say "returns" rather than "interest", but the effect is the same and our calculator works for both.
Monthly or yearly compounding: which is better?
Monthly compounding pays slightly more because interest starts earning its own interest sooner: CHF 10,000 at 5% gives CHF 16,470 after 10 years instead of CHF 16,289. Many Swiss savings accounts credit interest once a year. In the calculator you can pick monthly, quarterly or yearly compounding.
Can I use this as a Pillar 3a interest calculator?
Yes. Enter the maximum of CHF 7,258 a year as about CHF 605 a month, then your 3a account rate (1.00% at best) or the fund return you expect. To see how much tax you save and which provider is cheapest, use our Pillar 3a calculator.
Tips to Maximize Your Compound Growth
Start today, not next month Every month you delay costs you. Even if you can only invest CHF 50, start now and increase later.
Automate everything Set up automatic transfers to your Pillar 3a or investment account. Remove the decision from each month. You can't spend what you don't see.
Minimize fees relentlessly Compare providers. A Pillar 3a charging 1.2% vs. one charging 0.4% will cost you tens of thousands over your investment lifetime. This is one of the few variables you can actually control.
Reinvest all dividends Don't withdraw gains. Let them compound. Most Swiss investment products do this automatically, but check to be sure.
Increase contributions with salary raises Got a 3% raise? Increase your investment by 2% and enjoy 1%. You won't miss money you never had.
Stay invested during crashes Market crashes feel terrible. They're also the worst time to sell and the best time to buy more. The 2008 crash, the 2020 COVID crash... investors who stayed in recovered and then some.
The Bottom Line
Compound interest isn't magic, but it's close. The formula is simple: start early, contribute regularly, keep fees low, and don't touch it.
This calculator shows you the math. What you do with it is up to you.
Pro tip: Save your calculation using the share button. It creates a URL with all your inputs so you can revisit it later or share your scenario with a financial advisor.
Now run your numbers. Then compare them with our Pillar 3a comparison to find the lowest-fee provider for your situation. Because the best compound interest calculator in the world is useless if you're paying 1% more in fees than necessary.