Korean age calculator
Traditional Korean age counts you as one at birth and adds a year every 1 January rather than on your birthday. Someone born on 31 December is therefore two in Korean age the following day, while being one day old internationally.
How Korean age works
South Korea legally moved to international age in June 2023, ending a long-standing situation where three different age systems coexisted — traditional, international, and a "year age" used for school entry and military service. The traditional count has not disappeared from everyday speech, and it still shapes social hierarchy, since Korean speech levels depend on relative age. The calculation remains worth knowing even though the legal position has changed.
Questions
You are one at birth, and everyone gains a year on 1 January regardless of birthday.
One from being counted as one at birth, and another if your birthday has not yet passed this year.
Legally South Korea moved to international age in 2023, but the traditional count persists in everyday speech.
They turn two in Korean age the next day, at one day old.
Similar East Asian age reckoning existed in China, Japan and Vietnam but has largely fallen out of use.