Calculate age in completed years, months, and days from a birth date to any comparison date.
How age is calculated
Age is shown as completed calendar years, then completed months, then remaining days. The calculator uses calendar dates instead of dividing total days by 365.
Age = completed years + completed months + remaining calendar days
Birthdays on February 29
For the next-birthday display, February 29 is treated as February 28 in a non-leap year. Legal age rules can differ by jurisdiction.
Frequently asked questions
Does the calculator use my time zone?
It compares the entered calendar dates and does not use the current time of day.
Can the comparison date be before the birth date?
No. The age date must be the same as or later than the birth date.
Is this suitable for legal deadlines?
No. Legal age and deadline rules may use jurisdiction-specific counting methods.