Korean Age Calculator

This page shows three different calculations for the exact same dates.

• Full age starts at zero at birth and increases after each birthday. The formula is reference year minus birth year, then subtract one if the birthday has not yet occurred in the reference year.
• Traditional Korean counting age is reference year minus birth year plus one. It is a historical counting convention, so people born in the same calendar year share the same value from 1 January.
• Year age is reference year minus birth year, without checking whether the birthday has happened. It is another arithmetic convention that some rules have used for defined purposes.

Full age is the general civil and administrative default

Korea’s government guidance explains that, from 28 June 2023, full age is the general default for civil and administrative matters unless a law, contract or policy says otherwise. That does not turn this calculator into an eligibility checker. The same guidance identifies exceptions, including school entry and certain alcohol, tobacco and military rules. Always read the specific rule that applies to the decision you are making.

This tool does not determine whether someone is an adult, can buy a product, may enroll, can vote, qualifies for a benefit, meets a workplace rule or has any legal right. It only performs the three date calculations shown above.

Privacy and date limits

Your birth date and reference date stay in this browser session. They are not sent to our servers and are not included in the page address. Do not enter another person’s date of birth on a shared device without permission.

The calculator uses Gregorian calendar dates and rejects impossible dates or a reference date before birth. For a legal or administrative question, use the relevant Korean authority or service rather than relying on a general-purpose date calculation.

Source

• Korea Policy Briefing: guide to using full age explains the 2023 age-standardization change, the full-age formula and examples of exceptions.