What is the difference between international and Korean age?

International age is birthday-based (the global standard); Korean counting age counts the birth year as 1, so it is usually 1-2 years higher.

What changed with the 2023 age unification?

Since June 2023, international age is used by default in law, administration, and contracts unless stated otherwise — usually 1-2 years younger than the traditional Korean age.

How is age calculated for early-year births?

International age depends only on the birthday, so it is unaffected. Korean counting and year ages use only the birth year.

🎂

Age of People Born in 2017 (as of 2026) - Toolkit

People born in 2017 are 8-9 years old (international age) as of 2026, or 10 in Korean age.

2026International age (birthday-based)

Date of birth

Age

How age is calculatedShow steps

International age9

this year − birth year (−1 if birthday hasn't passed yet)

How it's calculated & notes

·International age counts completed years of life: (this year − birth year), minus 1 if your birthday hasn't occurred yet this year.
·It increases by 1 on each birthday.
·Different countries and cultures may count age differently, so a local reckoning can differ from this value.

Age for Those Born in 2017

As of 2026, someone born in 2017 is 10 in Korean counting age and 9 in year age. Their international age is 9 if their birthday has passed, or 8 if not.

By age type

International age (birthday passed): 9
International age (before birthday): 8
Korean counting age: 10
Year age: 9

What is the age calculator?

Since June 2023, Korea legally uses international age. International age increases by one on each birthday; Korean counting age counts the birth year as age 1 and adds a year each New Year; year age is the current year minus the birth year.

Age types

International age: birthday-based (legal standard since 2023)
Korean counting age: 1 at birth year, +1 each New Year
Year age: current year − birth year

View the full age-by-birth-year table →

Frequently Asked Questions

What is the difference between international and Korean age?: International age is birthday-based (the global standard); Korean counting age counts the birth year as 1, so it is usually 1-2 years higher.
What changed with the 2023 age unification?: Since June 2023, international age is used by default in law, administration, and contracts unless stated otherwise — usually 1-2 years younger than the traditional Korean age.
How is age calculated for early-year births?: International age depends only on the birthday, so it is unaffected. Korean counting and year ages use only the birth year.

Last updated: July 2026