Compound Interest
See how your money grows over time.
Parameters
Results
Return rate
after 3% inflation
Final balance
€37,405.09
nominal
Today's value
€27,832.90
inflation-adjusted
Inflation eroded €9,572.19 of your returns
Total contributions
€22,000.00
Interest earned
€15,405.09
Real gain
+€5,832.90 (+26.5%)
Over 10 years, your investment grows from €22,000.00 in contributions to a nominal €37,405.09. After accounting for 3% annual inflation, that's worth €27,832.90 in today's purchasing power — a real gain of +€5,832.90 over what you put in.
Growth Over Time
What does this mean in real life?
☕ Coffee costs approx. €3.50. With €1,000.00:
Today
285
coffees
In 10 years
212
due to inflation
The same amount buys 73 fewer coffeess after 10 years of 3% inflation.
Your €22,000.00 in contributions:
Kept as cash
€16,370.07
real value after 10y
Invested
€27,832.90
real value after 10y
Investing puts you €11,462.84 ahead in real terms compared to keeping cash.
Year-by-Year Breakdown
| Year | Balance | Contributions | Interest | Real Value |
|---|---|---|---|---|
| 1 | €12.0K | €11.2K | +€762.16 | €11.6K |
| 2 | €14.1K | €12.4K | +€1.7K | €13.3K |
| 3 | €16.3K | €13.6K | +€2.7K | €14.9K |
| 4 | €18.7K | €14.8K | +€3.9K | €16.7K |
| 5 | €21.3K | €16.0K | +€5.3K | €18.4K |
| 6 | €24.1K | €17.2K | +€6.9K | €20.2K |
| 7 | €27.1K | €18.4K | +€8.7K | €22.0K |
| 8 | €30.3K | €19.6K | +€10.7K | €23.9K |
| 9 | €33.7K | €20.8K | +€12.9K | €25.8K |
| 10 | €37.4K | €22.0K | +€15.4K | €27.8K |
Disclaimer: This calculator is for illustrative purposes only. It assumes a fixed annual return and does not account for taxes, fees, or market volatility. Past performance does not guarantee future results.
What is compound interest?
Compound interest is interest calculated on both your initial principal and the interest already accumulated. Unlike simple interest — which only grows on the original amount — compound interest grows exponentially over time. The longer the time horizon and the more frequently it compounds, the greater the effect.
For example, daily compounding will produce a higher final balance than annual compounding at the same nominal rate, because interest is reinvested more frequently — giving it more time to earn returns on itself.
How to use this calculator
- Initial investment — the lump sum you start with. Set this to 0 if you are starting from scratch.
- Monthly contribution — a fixed amount added every month. Even small regular contributions compound significantly over long periods.
- Annual interest rate — your expected average yearly return. Broad market index funds have historically returned around 7–10% annually before inflation.
- Inflation rate — when set above 0, the calculator shows the real value of your final balance in today's purchasing power.
- Compound frequency — how often interest is applied. Monthly is typical for most investment accounts.