How Age Is Calculated Around the World

How old are you? The answer depends on where you live and which cultural convention you follow.

Western Age Counting

In most Western countries, you are zero years old at birth and gain a year on each birthday. This is the most common system and what our Age Calculator uses.

East Asian Age Reckoning

In traditional Korean, Chinese, and Japanese systems, a baby is one year old at birth (counting time in the womb). Everyone gains a year on New Year Day, not their birthday. South Korea officially switched to the international system in 2023.

Lunar Calendar Ages

Some cultures calculate age based on lunar calendars. The Chinese zodiac follows a 12-year cycle. Islamic calendar years are shorter (354 days), so ages calculated in Hijri years differ from Gregorian ages.

Legal Age Definitions

Legal age calculations matter for voting, driving, drinking, and contracts. Most countries use completed years. Some use the calendar year of birth for school enrollment.

Fun Calculations

Our Age Calculator shows your age in years, months, days, and total days lived. It also tells you how many days until your next birthday. Try entering famous historical dates to see how long ago events occurred.