Age calculator
Calculate exact age in years from a date of birth, as of today or any other date. Also shows the next birthday and the number of days since birth.
How to use
- Choose the year, month and day of birth.
- The date for the age is set to today. Change it to see the age on a past or future date, such as a form's deadline.
- The age in completed years, the next birthday and the number of days since birth are shown.
- If the birthday is February 29, choose whether it counts on February 28 or March 1 in years without a February 29.
Notes and limits
- Age goes up by one on the birthday itself and is calculated in whole days (time of birth is ignored).
- For February 29 birthdays, the rule for common years differs by country and purpose. The tool uses March 1 unless you choose February 28. Check which rule applies if the age has legal effect.
- Other ways of counting age, such as counting from 1 at birth, are not calculated.
- The date of birth you enter is not sent or stored.
How it works
Age = year of the date − year of birth, minus 1 if the birthday has not yet come that year.
For someone born on February 29, the birthday in a common year is March 1 by default (as in Japanese law) or February 28 if selected. In leap years it is February 29.
Days since birth = the date − the date of birth, in calendar days.
FAQ
How do I find my age on a specific date?
Change "Age on this date" to that date. The age in completed years on that day is shown.
When does someone born on February 29 turn a year older?
In leap years, on February 29. In other years, conventions differ: some countries and services use February 28, others March 1. Pick the rule that fits your case in the option that appears for February 29 birthdays.
Is my date of birth saved?
No. The calculation runs in your browser, and nothing you enter is sent to a server or stored.
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