Calculator
Age calculator
This calculator shows calendar age and days until the next birthday. Today follows Europe/Warsaw and can be changed. Birth dates stay in your browser; this tool does not establish legal age.
Calculator
Enter data
Birth date and the date on which to calculate age. Fields marked with an asterisk are required.
How to use the calculator
- Enter the birth date and check the calculation date.
- Read completed years, remaining months and days, and the birthday countdown.
Calculation details
Formula and calculation method
Complete months are anchored to the original birth date, clamping a missing day to month end. Years = whole months divided by 12; remaining months and days follow the last anchor.
Worked example
A person born on 29 February 2000 is 25 under this convention on 28 February 2025. A birthday on the calculation date means zero days to wait.
Limitations
- 29 February → 28 February in non-leap years. This is a calendar convention, not the Polish rule for legal majority, eligibility or deadlines.
- Input dates 1900–2200; no birth time or time-zone conversion.
Sources
Engine version: 2.0 (2026-09-23) · Last reviewed: 23 September 2026
Frequently asked questions
Where does today come from?
From the device clock converted to Europe/Warsaw. Check your clock; you can edit the date.
Does this confirm legal majority?
No. Apply the relevant law and documents for formal decisions.