Compound interest calculator
Compare the gross balance, after-tax balance, contributions and purchasing-power value.
Sources and adopted values
- National Bank of Poland — reference information — This official source explains the rule used by the calculator.
- Polish Ministry of Finance — tax guidance — Official information about the 19% tax on selected capital income, including deposit interest.
Calculation schedule
| Year | Value | Value | Value | Value |
|---|---|---|---|---|
| Fill in the fields above — the result is computed on this page. | ||||
The table shows the calculation period by period using the assumptions entered above.
How do I use this page?
- Enter values from your current offer, agreement or official documents.
- Choose the options that match your actual situation.
- Calculate the result and compare the detailed components.
- Test an alternative scenario before making a decision.
What this page does not do: This is a mathematical scenario, not an investment forecast. Real returns, fees, taxes and inflation can differ.
Further reading
Theory — how does compound interest work with regular contributions?
The calculator compares the gross balance, after-tax balance, total contributions and the purchasing-power value of regular savings over time. Compound interest means that each calculation period applies to the initial capital, the result accumulated so far, and any contributions already sitting in the account. A contribution made at the start of a month earns one extra period of interest compared with a contribution made at the end, which adds up over many periods into a noticeable difference in the final balance.
Frequently asked questions
What does the compound interest calculator include?
Is this result exact?
Which values should I enter?
Can I use the result to compare scenarios?
Why can the real result differ?
See also
Bank deposit calculator
Calculate a deposit's gross and net interest after tax, including compounding, contributions and inflation.
PPK savings calculator
Estimate PPK savings from employee, employer and state contributions, assumed return and fees.
Percentage Calculator
Online percentage calculator: percentage of a number, share and percentage change, plus increasing or decreasi