A worked example
Age before a birthday
- Start with
- Born 2000-10-15 · reference 2026-08-28
- Check the result
- Age 25 · birthday in 48 days
The 2026 birthday has not yet occurred, so one is subtracted from the 26-year difference.
Everyday tool
Age Calculator
Enter birth and reference dates to see age on that date and the countdown to the next birthday.
February 29 birthdays use February 28 in non-leap years
Age on a selected dateChoose any reference date, including today or a future date.
Calendar ageHow completed age is calculated
Subtract the birth year from the reference year, then subtract one more year if the birthday has not occurred yet.
Calculated result
Age on Oct 10, 202636 years old36y 9m 9d
Total days lived13,431 days
Birth weekdayMonday
Next birthdayJan 1, 2027
Birthday countdownD-83
The result uses calendar dates and is intended as a general reference. A February 29 birthday is treated as February 28 in non-leap years.
Birthday-based age
Read age today or on a date you choose
Choose the reference date
Use today for current age, or choose a specific date such as an enrollment day or anniversary.
Read completed years and elapsed time
Results update when the dates change. Age counts completed years; elapsed time also shows months and days.
Check the next birthday
Read its date alongside the countdown. On the birthday itself, the result says Today; you can copy the result.