How is exact age calculated?
Complete calendar years are counted first, followed by complete months and remaining days.
Age Calculator
Calculate exact age, compare birthdays, and plan upcoming birthday milestones.
Workspace
Calculate age on any date
Use today or choose a past or future comparison date.
Choose a date of birth to see exact age, birthday, and milestone details.
Compare two ages
Enter another date of birth to calculate the exact age gap.
The selected leap-day convention affects anniversaries in non-leap years. Legal rules may differ by jurisdiction.
GuideHow to use
- Enter a date of birth, then keep Today selected or choose any later comparison date.
- For a 29 February birthday, choose whether non-leap-year anniversaries fall on 28 February or 1 March.
- Review exact age, elapsed months, weeks and days, upcoming birthdays, and the next five-year milestone.
- Copy the summary, export it as CSV, add the next birthday to a calendar, or compare two dates of birth.
HelpFrequently asked questions
Can I calculate age on a past or future date?
Yes. Change the comparison date to any date on or after the date of birth.
How are leap-day birthdays handled?
You can choose 28 February or 1 March for anniversaries in non-leap years. The selected convention is used consistently for exact age, birthday countdowns, and milestone dates.
Can I compare the ages of two people?
Yes. Enter another date of birth in Compare two ages to see the exact calendar gap, total days apart, and which person is older.
Can I save the next birthday?
Yes. Add to calendar downloads an all-day calendar event for the next birthday. You can also download the age summary as CSV.
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