Age · Next birthday · Countdown
Age calculator
Enter your date of birth. Optionally set a custom “as of” date/time.
Ready.
Results
Your exact age
Calendar age—
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Born on —
Next birthday
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Change leap-day preference if you were born on Feb 29.
About this age calculator
How it works
- We build UTC timestamps from your inputs to avoid DST errors.
- We compute calendar-aware years, months, and days (with proper borrowing).
- Totals (weeks, days, hours, minutes, seconds) come from the exact millisecond difference.
Edge cases & limitations
- Leap day (Feb 29): Choose Feb 28 or Mar 1 for non-leap years.
- Months vary: “1 month” follows calendar boundaries, not a fixed day count.
- Time zones: We detect your local time; custom “as of” uses your local zone.
For legal/official purposes, check local rules—this is educational only.
Examples
- 1990-05-12 → turns 35 on 2025-05-12.
- 2000-02-29 (pref Feb 28) → 2025 next birthday is 2025-02-28.
- 2000-02-29 (pref Mar 1) → 2025 next birthday is 2025-03-01.
Last updated:
FAQ
Do I need to enter a time?
No. If omitted, we use 00:00 at your local time zone. Toggle “include time” to add it.
Inclusive vs exclusive days?
We report elapsed time up to the exact moment of the “as of” timestamp. Days are whole-day floors based on exact milliseconds.
Why do totals not equal simple averages?
Because calendar months have different lengths. We show both calendar-accurate Y/M/D and flat totals (weeks/days/hours).
Methodology & references
We follow standard calendar arithmetic and compute age in UTC to avoid daylight-saving anomalies. Outputs are displayed using your locale/time zone.