A LITTLE GUIDANCE
Age Calculator — Years, Months & Days Lived guide
Find completed years of age by comparing the birthday with today or a chosen date.
How to use
- Enter the birth date.
- Choose a reference date or set it to today.
- Read completed years, elapsed months and days lived.
Worked example
- Input
- Birth date: 2000-01-01. Reference date: 2026-01-01.
- Result
- The result is 26 completed years, 312 elapsed months and a difference of 9,497 days.
Common questions
Is the day of birth counted as day one?
No. Days lived is the difference between the two dates. The birth date itself is day zero and the next day is day one.
How are February 29 birthdays handled in non-leap years?
This tool treats March 1 as the point when that birthday has passed. The today button uses the date in Korea Standard Time.