Age Calculator

The calculator computes the difference between your date of birth and the current date (or a specified reference date). International age counts completed years: the number of full years elapsed since the birth date. If today's month/day is before the birth month/day, the age is reduced by one.

Korean age uses a different system: you are 1 at birth and gain one year every January 1st, regardless of your actual birthday. The formula is: Korean age = current year − birth year + 1. Note that as of June 2023, South Korea officially adopted the international age system for legal and administrative purposes, but Korean age is still widely used in everyday conversation.

The remaining days to the next birthday are calculated by finding the next occurrence of the birth month/day and computing the day difference from today.