How to use this tool
Enter the birth date and the date on which you want to measure age.
Read the completed years and full calendar breakdown. For a historical reference, change Age on date rather than relying on today.
Completed calendar years + completed calendar months + remaining days
Worked example
26 · completed years
Fixed example using the settings below. Monetary examples use USD; dates and times use their stated reference values. This example stays unchanged when you edit your calculation.
Example inputs
- Date of birth: 2000-01-01
- Age on date: 2026-01-01
Method illustration: Someone born on January 1, 2000 is 26 years old on January 1, 2026.
Assumptions and limits
- Uses Gregorian calendar anniversaries, rather than dividing days by 365.
- An anniversary falling beyond a month's last day is clamped to that month's last day. February 29 birthdays use February 28 in non-leap years.
- Results are for calendar planning, not jurisdiction-specific legal age decisions.
Check or report a result
Check the units, selected calculation and assumptions first. Compare the fixed example above with your inputs to identify what changed.
Report a calculation issue with the page address, hypothetical inputs, result displayed and result expected. Do not include passwords, bank details or other private information.