Age calculator
Enter a date of birth and a reference date. AlarmPick shows the completed age, the years, months, and days, the calendar days lived, and the next birthday. The count uses calendar dates, so a local day of 23 or 25 hours does not change it. The birth date is not saved. You can use it at no charge.
What is an age calculator?
An age calculator turns a birth date and a reference date into an age. AlarmPick uses the completed age, the age people also call full years, plus the months and days that remain. It does not count hours.
How age is calculated
The calculator compares the two calendar dates. If the birthday has not yet occurred in the reference year, the completed age is the year gap minus one. If the birthday is that day or has already passed, the completed age is the year gap. A future reference date is allowed. A reference date before the birth date is not.
Completed age and the full calendar age
The completed age is the number of full years. The longer result keeps the years and adds the months and days from the birth date to the reference date. On the birthday itself, the months and days are zero.
February 29 birthdays
A February 29 birthday is kept on February 29 in a leap year. In a year that is not a leap year, that birthday is February 28. On 28 February of such a year, the birthday counts as reached. It does not move to March.
Total days and the next birthday
Total days are calendar days from the birth date to the reference date. The same date is 0 days, and the next date is 1 day. If the birthday is still ahead this year, the next birthday is this year's date. If today is the birthday, the page says so and the days remaining are 0. If this year's birthday has passed, the next birthday is next year's date, using February 28 when that year has no February 29.
Common uses
- How old you are today.
- How old you were, or will be, on another date.
- How many calendar days you have lived, and how many days remain until the next birthday.
Limitations
- This page calculates a completed age from calendar dates. It does not calculate Korean counting age.
- It does not use the length of a local day, so daylight saving time does not change the age or the day count.
- Years run from 1 through 9999. A next birthday outside that range is rejected.
- Hours and minutes are not part of this calculator.
- The birth date and the reference date are not saved in this browser, and they are not sent to a server.
- The suggested reference date is today on this device. It is filled after the page opens and is not written into the page file. The birth date stays empty until you enter it.
Questions
How old am I?
Enter your date of birth, keep or change the reference date, and press Calculate. The completed age is the number of full years reached on that date.
How is age calculated?
Subtract the birth year from the reference year. If the birthday in that reference year has not happened yet, subtract one more year. February 29 falls on February 28 when the reference year is not a leap year.
How old am I in years, months, and days?
The result lists the full years, then the months and days from the birth date to the reference date. Those parts use the same calendar rules as the completed age.
How many days old am I?
Total days are the calendar days from the birth date to the reference date. The birth date itself is 0 days. The next day is 1 day.
How many days until my next birthday?
The page counts calendar days from the reference date to the next birthday. If the birthday is today, that count is 0.
How is a February 29 birthday handled?
In a leap year the birthday stays on February 29. In any other year it is treated as February 28, for the age, the next birthday, and the days remaining.
Can I calculate my age on another date?
Yes. Change the reference date and press Calculate. A future date is allowed. A date before the birth date shows a message instead of an age.