Age Calculator
Enter your date of birth to get your exact age in years, months and days, plus the days until your next birthday. Change the reference date to find your age on any past or future day.
Change the reference date (defaults to today)
Enter a date of birth to see the age.
How to use
Enter a date of birth and the exact age in years, months and days appears instantly, along with the number of days until the next birthday. There is no submit button.
Open "change the reference date" to find someone's age on a specific past or future day — their age at a wedding or retirement date, how old they will be in a given year, or confirming an age for a form or application. It also handles edge cases like leap-day birthdays correctly.
How age is counted
Age here is the exact difference in whole years, then the remaining whole months, then the remaining days — counted on the calendar, not by a flat "30 days per month." This matches how a person naturally states an age: you turn a year older on your birthday, and the months and days count the time since that last birthday.
Leap-day birthdays are handled to match the legal convention: someone born on February 29 is treated as turning a year older on February 28 in common (non-leap) years, and on February 29 in leap years. All counting is done on a timezone-independent calendar basis, so you get the same result regardless of your device's region settings.
FAQ
- Why is the age the day before a birthday not a full year?
- Age increases on the birthday itself. The day before, the person is still the previous age — the months and days show how close they are, so the day before a 36th birthday shows as 35 years, 11 months and some days.
- How are leap-day (February 29) birthdays handled?
- In common years that have no February 29, this tool treats the birthday as February 28 for the purpose of turning a year older, matching the usual legal convention. In leap years the birthday falls on February 29 as normal.
- Can I find someone's age on a specific date?
- Yes. Open "change the reference date" and set any date to get the age as of that day, in the past or the future. If you just want the number of days between two dates, use the separate Date Calculator instead.