Native vs Sino-Korean Numbers: When to Use Which System

Korean uses native Korean numbers (하나, 둘, 셋) for counting things, age and clock hours, and Sino-Korean numbers (일, 이, 삼) for dates, money, minutes, phone numbers and almost everything above 99.

That sounds like a lot to memorize, but the split follows a pattern. Once you see it, you will pick the right system without thinking.

What are the two Korean number systems?

Native Korean numbers are the original Korean words. Sino-Korean numbers come from Chinese characters, the same way English has both “hundred” (Germanic) and “century” (Latin).

Notice the Sino-Korean side is pure logic: 이십 is literally “two-ten.” The native side has a new word for every ten, which is why learners find it harder.

Native numbers stop at 99

Native Korean counts up to 아흔아홉 (aheun-ahop, 99). There is no native word in daily use for 100, so from 100 on everyone switches to Sino-Korean: 백 (baek), 천 (cheon), 만 (man).

That means “100 people” is 백 명 (baek myeong), even though “20 people” is 스무 명 (seumu myeong). In real life, many speakers also drift to Sino-Korean for big counts in the 50s to 90s, because 일흔여덟 is a mouthful.

When do you use native Korean numbers?

Think “how many” and “how old.” Native numbers count real, physical things and people, usually with a counter word after them.

• Counting things and people: 사과 세 개 (sagwa se gae, three apples), 친구 두 명 (chingu du myeong, two friends)
• Age in everyday speech: 스물다섯 살 (seumul-daseot sal, 25 years old)
• Clock hours: 세 시 (se si, three o’clock)
• How many times: 한 번 (han beon, once), 두 번 (du beon, twice)
• Months as a length of time: 두 달 (du dal, two months)

The 하나 → 한 contraction

Here is the rule that trips everyone up. When 1, 2, 3, 4 and 20 sit right before a counter, they get shorter.

The contraction also happens inside bigger numbers: 열한 개 (yeolhan gae, 11 things), 스물두 살 (seumul-du sal, 22 years old). But 스물 only shortens when it stands alone before the counter, so 21 is 스물한 살, not 스무한 살.

When do you use Sino-Korean numbers?

Think “which one,” “how much” and “what number.” Sino-Korean handles labels, measurements and anything that can get large.

• Dates: 시월 십구 일 (siwol sipgu il, October 19)
• Money: 오천 원 (ocheon won, 5,000 won)
• Minutes and seconds: 삼십 분 (samsip bun, 30 minutes)
• Phone numbers, floors, room and bus numbers: 삼 층 (sam cheung, third floor), 칠 번 버스 (chil beon beoseu, bus number 7)
• Measurements: 오 킬로 (o killo, 5 kilos), 이십 도 (isip do, 20 degrees)
• Formal age: 이십오 세 (isibo se, 25 years of age), used on forms, news and documents

Hours vs minutes: one sentence, two systems

Time is the classic example of both systems in one breath. The hour is native, the minutes are Sino-Korean.

There is a full guide to this in telling time in Korean.

A neat trick: 분 after a native number means "people" (polite), and after a Sino number it means "minutes." 세 분 (se bun) is "three people," 삼 분 (sam bun) is "three minutes."

How do you say phone numbers in Korean?

Phone numbers are read digit by digit in Sino-Korean. Zero is usually 공 (gong) instead of 영 (yeong), and the dash is often read as 에 (e).

How do you say your age?

In conversation, use native numbers plus 살 (sal). On paper, at the doctor or in the news you will see Sino-Korean plus 세 (se).

Since June 2023 Korea officially counts age the international way, so the number you say should match your passport age. More on that in how to say dates and birthdays in Korean.

A quick decision checklist

When you are not sure, ask yourself one question: am I counting how many, or naming which one?

Practice without memorizing tables

The fastest way to get comfortable is to say real numbers out loud: your age, your phone number, the time right now, the price of your last coffee. Type any number into the Korean number converter and it shows you both systems side by side, plus money, dates and time.

If you are still shaky on reading the Hangul itself, warm up with the Hangul reading quiz first. Numbers are much easier once 열, 일 and 이 stop looking alike.

Sources: National Institute of Korean Language (국립국어원) Standard Korean Language Dictionary and romanization rules; Ministry of Government Legislation notice on the unified international age system (June 28, 2023).

We follow the rules of the National Institute of Korean Language. Spotted a mistake? Tell us and we'll fix it.