Age Calculator
Find completed years, total calendar days lived, and the next birthday from two dates.
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How to use Age Calculator
Calculate age on any chosen reference date. Date-only inputs are evaluated consistently in the Gregorian calendar, so daylight-saving clock changes do not alter the day count.
- Choose a date of birth.
- Choose the reference date for the age calculation.
- Read completed years, elapsed calendar days, and the next birthday.
Good to know
- For February 29 births, March 1 is treated as the anniversary in non-leap years. Legal age rules may differ.
- Years 0001–9999 are supported. Times of birth and local time zones are not considered; the default reference date uses UTC.
Common questions
What happens on the birthday itself?
The new completed year is counted on that date. The next birthday shown is today and the remaining day count is zero.
Why can the default date differ from my local date?
The initial reference date is based on UTC. Near midnight, your local calendar date may be different; select the desired date explicitly.
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