Age on a specific date
See exactly how old someone is on the day you choose.
Age on the selected date
How old on a particular day?
Enter a birth date and an as of date to see complete years, months and days.
Choose the date that matters
- Enter a date of birth.
- Choose an “as of” date, past or future. It starts with your device’s today.
- Calculate, then copy the result if useful.
Need the interval between any two dates? Use Date difference.
How the calendar age works
What happens at month-end or on February 29?
We first count complete years from the original birthday, clamping a missing day to the last day of that month. Then we count 0–11 complete months. Every year-and-month candidate starts from the original birthday and clamps only in the target month; a February clamp does not permanently change the birth day. The remaining days are actual elapsed days.
February 29, 2000 → February 28, 2023 is 23 years, 0 months, 0 days. January 31 → March 30, 2023 is 0 years, 1 month, 30 days; March 31 is 0 years, 2 months, 0 days. February 29, 2000 → February 28, 2024 is 23 years, 11 months, 30 days: the last month anchor is January 29, and the next original birthday is still one day away.
Is this a legal or official age determination?
No. This is a Gregorian calendar calculation using the convention above. Laws, admission rules and other calculators may use different conventions. Check the relevant authority for eligibility.
Are birthdays uploaded or saved?
No. Dates and results stay in the page’s memory. They are never added to the URL, stored in browser storage or included in analytics.