Calculate your exact age in years, months and days from your date of birth. Includes next birthday countdown.
Calculate your exact age in years, months, and days from any date of birth to any reference date (default: today). The calculator also shows how many days until your next birthday. Useful for age verification, filling out forms, genealogy research, or satisfying curiosity.
The calculator computes the difference between your date of birth and the reference date accounting for variable month lengths and leap years. It first calculates full years, then remaining full months, then remaining days. This matches how age is counted in everyday life — a person born on January 31 turns one year old on January 31 of the following year, not on February 1 (even though February has fewer days than January).
The tool finds the next occurrence of your birthday month/day after the reference date and calculates the number of days remaining. If your birthday falls on February 29 in a non-leap year, the countdown targets March 1. The countdown resets to 365 (or 366) days the day after your birthday.
Chronological age is the number of years since your birth. Biological age reflects how your body has actually aged based on health, lifestyle, and genetics — it can be older or younger than chronological age.
The calculation is based on dates only (year, month, day). If you were born close to midnight, the precise age in hours or minutes may vary depending on time zone.
How Age Is Calculated: Years, Months, and Days