Investing
Compound interest: how money multiplies and why time beats amount
The formula in plain words, the rule of 72 and calculations that show why ten years of head start matter more than the size of your deposit.
Compound interest calculator
Final balance
UAH 832,650
- Contributed
- UAH 250,000
- Interest
- UAH 582,650
Growth by year
ContributedInterest
Year-by-year table
| Year | Contributed, UAH | Interest, UAH | Balance, UAH |
|---|
How to use the calculator
- Starting amount: how much you invest upfront. If you are starting from zero, enter 0.
- Monthly deposit: how much you plan to add each month. The calculator assumes each deposit arrives at the end of the month.
- Rate: the annual return in percent. For a deposit, use the bank's rate; for long-term investing, a conservative estimate of the average return.
- Compounding: how often accrued interest is added to the balance: monthly, quarterly or yearly. Check your deposit terms.
- Term: how many years you are planning for.
The result updates instantly. The chart shows how the balance grows year by year and how much of it comes from your deposits and how much from interest. Hover over or tap a bar to see the exact figures for that year. All inputs are saved in the page address, so you can share the calculation as a link.
Formula
The calculator works the way banks do: interest accrues every month on the current balance and is added to it at each compounding date. Every deposit starts earning interest from the following month. With monthly compounding this gives the classic future value formula for regular contributions. More on how compound interest works in “Compound interest: how money multiplies”.
Worked examples
FAQ
How is compound interest different from simple interest?
Simple interest is always calculated on the starting amount, so the income is the same every year. Compound interest is charged on both your deposits and the interest already earned, so the balance grows faster and faster. For example, UAH 100,000 at 10% for 30 years gives UAH 400,000 with simple interest and UAH 1,744,940 with compound interest (compounded yearly).
Does the calculator account for taxes and inflation?
No, it shows the nominal result before tax. To account for tax on deposit interest, reduce the rate by the tax share (current rates are on the State Tax Service website). To see the real return, subtract expected inflation from the rate: for example, 12% a year with 8% inflation is about 4% real return.
What rate should I enter?
For a deposit, the rate from the contract and the compounding frequency from its terms. For long-term saving in instruments with a variable return, use a conservative estimate and run several scenarios: pessimistic, base and optimistic. No rate is guaranteed for years ahead.
How do I share my calculation?
All inputs are saved in the page address automatically. Press “Share” to send the link in a messenger, or “Copy result” to get a short text with the result and the link. Anyone who opens the link sees your calculation with the same numbers.
The calculation is for reference only and is not financial advice. Actual returns depend on the bank or instrument, taxes and rate changes.
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