Age Calculator
Find an exact age in years, months, and days on any date you choose, plus total days lived and how long until the next birthday. Calendar math is exact, including leap years.
Your results
Worked example
Born February 29, 2000 (a leap day), age as of March 1, 2024:
- Whole years: Feb 29, 2000 to Feb 29, 2024 is exactly 24 years
- Remaining days: Feb 29 to Mar 1 is 1 day, so the exact age is 24 years, 0 months, 1 day
- Total days: 24 years hold 6 leap days (2004, 2008, 2012, 2016, 2020, and Feb 29, 2024 itself), so 24 × 365 + 6 = 8,766 days to Feb 29, 2024, plus 1 = 8,767 days
- Next birthday: 2025 has no Feb 29, so the birthday is observed on March 1, 2025, which is 365 days after March 1, 2024
How this calculator works
Age is counted with exact calendar arithmetic, the same way you would count it by hand:
Total days is a straight day count between the two dates, so every Feb 29 in between is counted. For people born on Feb 29, this calculator observes the birthday on March 1 in years without a Feb 29. That is a common convention, though some families and some official forms use Feb 28 instead.
Common questions
Why is there an "as of" date?
Age depends on the day you measure it. The as-of field lets you answer questions like "how old will she be on her wedding day" or "was he 18 on the day he signed" without doing calendar math by hand. Set it to today for a current age.
How are leap day (Feb 29) birthdays handled?
Exactly, in leap years: a person born Feb 29, 2000 turned exactly 24 on Feb 29, 2024. In years without a Feb 29, this calculator observes the birthday on March 1. If an official form or insurer uses Feb 28, ages near that boundary can differ by a day, so check the rule that applies to your situation.
General information only. Ages are computed with standard calendar rules as described on this page. Eligibility rules for pensions, licences, benefits, and insurance use their own definitions of age and may differ. Confirm any age that affects a legal or financial decision with the organization involved.