Age Calculator
Find your exact age in years, months, and days. Enter a date of birth and optionally choose the date you want the age calculated for.
Enter your date of birth to calculate your age.
How it works
Age is calculated on the UTC calendar: years, months, and days between your date of birth and the “age as of” date. Months and days borrow from larger units when needed, matching how ages are usually stated in everyday life.
By default, the as-of date is today in UTC. You can change it to see how old someone was on a past date or will be on a future date. The date of birth must be on or before the as-of date.
Examples
The result is always expressed as years, then months, then days—not a single total in days.
Birthday today
If today is your birthday, years increase by one and months and days reset to 0 (for example, 30 years, 0 months, 0 days).
End of month birth date
Born on January 31 and as-of March 28? The calculator uses calendar months, so partial months reflect real month lengths.
Historical as-of date
Set as-of to a past event (such as a graduation date) to see exactly how old someone was on that day.
FAQ
- Why UTC for age?
- Date-only fields use UTC midnight so everyone sees the same age for the same birth date and as-of date, without local midnight shifting the calendar day.
- Can the as-of date be before birth?
- No. If the as-of date is earlier than the date of birth, the calculator shows zero years, months, and days.
- How is this different from days between dates?
- Days Between counts a single span in days. Age breaks that span into years, months, and days the way people describe age in conversation.