Compound Interest Calculator
How much of the result came from deposits and how much from time
Result
Growth over time
Year by year
| Year | Deposited | Interest that year | Interest | Balance |
|---|---|---|---|---|
| 1 | CZK 160,000 | CZK 9,192 | CZK 9,192 | CZK 169,192 |
| 2 | CZK 220,000 | CZK 14,194 | CZK 23,386 | CZK 243,386 |
| 3 | CZK 280,000 | CZK 19,557 | CZK 42,943 | CZK 322,943 |
| 4 | CZK 340,000 | CZK 25,309 | CZK 68,252 | CZK 408,252 |
| 5 | CZK 400,000 | CZK 31,475 | CZK 99,727 | CZK 499,727 |
| 6 | CZK 460,000 | CZK 38,088 | CZK 137,815 | CZK 597,815 |
| 7 | CZK 520,000 | CZK 45,179 | CZK 182,994 | CZK 702,994 |
| 8 | CZK 580,000 | CZK 52,782 | CZK 235,777 | CZK 815,777 |
| 9 | CZK 640,000 | CZK 60,935 | CZK 296,712 | CZK 936,712 |
| 10 | CZK 700,000 | CZK 69,678 | CZK 366,390 | CZK 1,066,390 |
| 11 | CZK 760,000 | CZK 79,052 | CZK 445,443 | CZK 1,205,443 |
| 12 | CZK 820,000 | CZK 89,104 | CZK 534,547 | CZK 1,354,547 |
| 13 | CZK 880,000 | CZK 99,883 | CZK 634,430 | CZK 1,514,430 |
| 14 | CZK 940,000 | CZK 111,441 | CZK 745,871 | CZK 1,685,871 |
| 15 | CZK 1,000,000 | CZK 123,835 | CZK 869,706 | CZK 1,869,706 |
| 16 | CZK 1,060,000 | CZK 137,124 | CZK 1,006,830 | CZK 2,066,830 |
| 17 | CZK 1,120,000 | CZK 151,374 | CZK 1,158,205 | CZK 2,278,205 |
| 18 | CZK 1,180,000 | CZK 166,655 | CZK 1,324,859 | CZK 2,504,859 |
| 19 | CZK 1,240,000 | CZK 183,039 | CZK 1,507,898 | CZK 2,747,898 |
| 20 | CZK 1,300,000 | CZK 200,609 | CZK 1,708,507 | CZK 3,008,507 |
What compounding actually does
Interest is earned on the interest already credited. That is why the curve looks almost straight for the first few years and only then bends upward — and why the time horizon matters more than the size of the deposit. The calculator runs month by month: interest on the balance first, then the deposit. The final month's deposit therefore earns nothing yet, exactly as in a real savings plan.
The return you enter is nominal. What counts is what survives inflation, which is why the final amount comes with its value in today's money. Seven percent a year against two percent inflation is under five in real terms. The calculator ignores capital gains tax and fund fees; both cut the result further.
The one number worth remembering is the rule of 72: seventy-two divided by the return in percent is roughly how many years it takes to double your money. Ten years at seven percent, six at twelve. None of it is guaranteed — historical averages of stock indices or bitcoin promise nothing about the future.