Calculate age in completed years on any date, with the total days lived and the days remaining until the next birthday.
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Someone born on June 15, 2010 is 16 on September 15, 2026, has lived 5,936 days and has 273 days until the next birthday. A person born on December 31, 1990 is still 35 on December 30, 2026 and turns 36 the next day.
The tool subtracts the birth year from the target year and then checks whether the birthday has been reached by the target date; if not, it subtracts one year. Total days are counted between the two calendar dates, so leap days are included exactly. Days until the next birthday count forward from the target date, and on the birthday itself the next one is a year away, shown as 365 days in 2026.
For a February 29 birth date, the tool uses February 28 as the birthday in non-leap years, so someone born on February 29, 2000 is 24 on February 27, 2025 and 25 on February 28, 2025. Some laws use March 1 instead. The birth date must not be later than the target date, and dates are compared as local calendar days without a time of birth.
Enter the date of birth and the date on which you need the age. The result is the number of birthdays that have fully occurred by that date, followed by the total days lived and the days until the next birthday. Someone born on June 15, 2010 is 16 on September 15, 2026, with 5,936 days lived and 273 days until the next birthday. The target date can be in the past or future, which is useful for eligibility cut-off dates, school entry or an age on a contract date.
A person born on December 31, 1990 is 35 on December 30, 2026 and turns 36 on December 31. The day count changes by one, but the age changes only when the birthday is reached. Dividing total days by 365 is not reliable: leap days accumulate, so 13,148 days ÷ 365 is slightly more than 36 even though the 36th birthday has not yet arrived. Use the completed-year result whenever a rule refers to a person’s age.
For a February 29 birth date, this tool treats February 28 as the birthday in non-leap years. A person born on February 29, 2000 is 24 on February 27, 2025 and 25 on February 28, 2025. Some laws or organizations use March 1 instead, and some count an age as reached at the end of the previous day, so check the rule that applies to your purpose. Dates are compared as local calendar dates without a time of birth or time zone, so the hour of birth does not affect the result.
| Input | Result |
|---|---|
2010-06-15 → 2026-09-15 | 16 y · 5,936 d · 273 d |
1990-12-31 → 2026-12-30 | 35 y · 13,148 d · 1 d |
1990-12-31 → 2026-12-31 | 36 y · 13,149 d · 365 d |
2000-02-29 → 2025-02-27 | 24 y · 9,130 d · 1 d |
2000-02-29 → 2025-02-28 | 25 y · 9,131 d · 365 d |
Leap days accumulate, so a day count divided by 365 runs slightly ahead of real birthdays. Someone born on December 31, 1990 has lived 13,148 days on December 30, 2026, slightly more than 36 × 365, yet the 36th birthday is still a day away. Legal and school age rules count completed birthdays.
Yes. Set the target date to any day on or after the date of birth, such as a school entry cut-off, a contract date or a birthday in a future year. The result shows the age reached on that day, not the age today, which makes it useful for checking eligibility rules in advance.
They count forward from the target date to the next birthday. On December 30, 2026, a person born on December 31 has 1 day to go. On the birthday itself the count restarts, so December 31, 2026 shows 365 days until the following birthday.