Korean Age Calculator: International vs Korean Age (Se-neun Nai)

Calculate your “Korean Age” (Se-neun Nai) and compare it with your International Age. Understand the differences between Man Nai, Yean Nai, and Se-neun Nai systems.

Korean Age Calculator

International Age (Man Nai)
--
--
Korean Age (Se-neun)
Traditional social age (1 @ birth, +1 Jan 1)
--
Year Age (Yeon Nai)
Current Year - Birth Year (0 @ birth, +1 Jan 1)

Understanding the Systems

📜 Note on 2023 Law Change: As of June 2023, South Korea officially adopted the "International Age" (Man Nai) for most legal and administrative purposes. However, the traditional "Korean Age" is still commonly used in social settings.
$$ \text{International} = \text{Current} - \text{Birth} \text{ (Adjust for birthday)} $$ $$ \text{Korean (Traditional)} = (\text{Current Year} - \text{Birth Year}) + 1 $$ $$ \text{Year Age} = \text{Current Year} - \text{Birth Year} $$