Find completed years, months and days between a date of birth and a reference date, as well as total elapsed calendar days.
Count completed anniversaries, then completed calendar months, then remaining days. Month shifts are limited to the last valid day of the target month.
Someone born on September 20, 2000 is 25 years old on September 15, 2026, and turns 26 five days later. A birthday later in the current year has not yet been completed.
For February 29 births, this tool treats March 1 as the anniversary in a non-leap year. Laws may use another rule. Months have unequal lengths, so decimal years and total days do not convert exactly into calendar years and months.
Editorial responsibility: Nicolas Belotti · Methods and testing · Report an error
English edition: 16 September 2026.