🎂 Age Calculator
Calculate exact age from a birth date. See years, months, days, total days lived, and how long until your next birthday — all in your browser.
Enter your date of birth to see your exact age.
About the Age Calculator
This age calculator computes an exact age between two dates. Pick your date of birth and a target date (today by default), and the tool breaks the difference into years, months, days, plus totals like total months, total weeks, total days, total hours, and total minutes. It also shows the weekday you were born and how many days remain until your next birthday.
How the calculation works
- Years / months / days — A calendar-based difference, borrowing days from the previous month and months from the previous year when needed. This matches how age is normally expressed.
- Totals — Derived from the raw millisecond difference between the two dates, then converted to weeks, days, hours, and minutes.
- Next birthday — Finds the next occurrence of your birth month and day on or after the target date and counts the days remaining.
How to use
- Open the date picker under Date of birth and select the day you were born.
- Optionally change Calculate age on to compute your age on a past or future date.
- Click Calculate. The result panel updates with the full breakdown.
- Use Use today to reset the target date to today.
Frequently asked questions
Does this tool store my birthday? No. The calculation is done entirely in your browser. Nothing is uploaded or saved.
Can I calculate age at a future date? Yes. Set Calculate age on to any future date to see the projected age on that day.
Why does the day count sometimes look off by one? Day borrowing depends on the number of days in the previous month relative to the target date. The calendar-based method matches everyday age conventions rather than simple 365-day divisions.
What about leap years? The calculator uses real calendar dates, so leap years and varying month lengths are handled correctly.