Korean Numbers: Complete Guide to Both Counting Systems

Why Korean Has Two Number Systems

One of the first surprises for Korean learners is discovering that Korean has not one but two complete number systems. The Native Korean system (고유어 수사, goyueo susa) is the original Korean counting system, while the Sino-Korean system (한자어 수사, hanjaeo susa) was borrowed from Chinese through centuries of cultural and linguistic contact. Each system has its own set of words for numbers, and each is used in specific, well-defined contexts.

This dual system might seem overwhelming at first, but there is good news: the rules for when to use each system are quite consistent. Once you learn the patterns, choosing the right system becomes intuitive. The key is to learn numbers in context — not just the words themselves, but the situations where each system applies. This approach aligns with how spaced repetition works: learning words in meaningful contexts makes them stick much better than rote memorization.

If you are curious about the Hanja (Chinese characters) behind the Sino-Korean numbers, knowing them can deepen your understanding of why certain numbers are used in certain contexts. The Sino-Korean numbers use the same characters as Chinese and share similarities with the number systems in other East Asian languages.

Native Korean Numbers: 하나, 둘, 셋 (1-99)

The Native Korean number system covers numbers from 1 to 99. For numbers 100 and above, Korean exclusively uses the Sino-Korean system. Here is the complete table of Native Korean numbers:

Native Korean Numbers 1-10

Notice the "Before Counter" column. The first four numbers (하나, 둘, 셋, 넷) change to shortened forms (한, 두, 세, 네) when placed directly before a counter word. Numbers 5 and above stay the same. This is one of the most common mistakes beginners make, so pay special attention to it.

Native Korean Tens (10-90)

To form compound numbers like 25, combine the tens word with the ones word: 스물다섯 (seumul-daseot). For 37, it is 서른일곱 (seoreun-ilgop). Note that 스물 (20) becomes 스무 (seumu) before a counter: 스무 살 (seumu sal — 20 years old), but stays 스물 in isolation or with another number: 스물다섯 (25). In practice, Native Korean numbers above 50 are rarely used in everyday conversation — Koreans increasingly use Sino-Korean numbers for larger quantities.

Sino-Korean Numbers: 일, 이, 삼 (1 and Beyond)

The Sino-Korean number system has no upper limit and is used for all numbers 100 and above. It follows a logical base-10 structure that is relatively straightforward once you learn the core building blocks. If you have studied Hanja, you will recognize these numbers as the Korean readings of Chinese characters.

Sino-Korean Numbers 1-10

Sino-Korean Large Number Units

The Sino-Korean system builds numbers logically. 11 is 십일 (sibil — ten-one), 25 is 이십오 (isibo — two-ten-five), 100 is 백 (baek), 347 is 삼백사십칠 (sambaeksasipchil — three-hundred-four-ten-seven). The system is regular and predictable, making it easier to learn than the Native Korean system for larger numbers. One critical difference from English: Korean groups large numbers by 만 (man, ten thousand) rather than by thousands. So 100,000 is 십만 (simman — ten ten-thousands), not "one hundred thousand." This grouping takes practice for English speakers.

Korean Counters: The Essential List

Counters (분류사, bunryusa) are classifier words required when counting specific objects in Korean. You cannot just say "three apples" — you must say "apples three [counter for items]." Counters use Native Korean numbers. Here are the essential counters every learner needs. For a deeper exploration of this topic, check out our dedicated Korean counters guide.

The word order for counters in Korean is: Noun + Number + Counter. For example, 사과 세 개 (sagwa se gae) literally translates to "apple three items." You can also put the number and counter before the noun with the particle 의 (ui): 세 개의 사과 (se gaeui sagwa — three items of apple), but the first pattern is more common in casual speech.

Telling Time in Korean: Where Both Systems Meet

Time is where the two Korean number systems collide in the most confusing way possible. Hours use Native Korean numbers, and minutes use Sino-Korean numbers. This mixing is one of the most common stumbling blocks for Korean learners, but once you internalize the pattern, it becomes second nature.

Hours (Native Korean + 시)

Minutes use Sino-Korean numbers with 분 (bun): 십 분 (sip bun — 10 minutes), 이십오 분 (isibo bun — 25 minutes), 삼십 분 (samsip bun — 30 minutes, also called 반 ban meaning "half").

Full time examples: 3:30 PM is 오후 세 시 삼십 분 (ohu se si samsip bun) or 오후 세 시 반 (ohu se si ban). 7:45 AM is 오전 일곱 시 사십오 분 (ojeon ilgop si sasibo bun). The AM/PM markers 오전 (ojeon) and 오후 (ohu) go at the beginning. Understanding Korean sentence structure will help you place time expressions correctly in full sentences.

Money: Counting in Won (원)

Korean money uses Sino-Korean numbers exclusively with the currency unit 원 (won). The key challenge for English speakers is that Korean groups large numbers by 만 (man, 10,000) rather than by thousands. Here are common price points you will encounter in Korea:

The trickiest part of Korean money for English speakers is the 만 (man) grouping. When you see 150,000원, think of it as 15만 원 (sibo-man won — fifteen ten-thousands won) not as "one hundred fifty thousand." Practice converting English thousands into Korean 만 units: divide by 10,000 and express the result. 230,000 becomes 이십삼만 (isipsamman — twenty-three ten-thousands). This skill is essential for shopping, dining, and the TOPIK listening section.

Age in Korean: 살 vs. 세

Age uses different number systems depending on formality. In casual conversation, Koreans use Native Korean numbers with the counter 살 (sal — years old). In formal or written contexts, Sino-Korean numbers with 세 (se — years of age) are used. Note that Korea has transitioned to using international age (만 나이, man nai) rather than the traditional Korean age system as of 2023.

In everyday conversation, "몇 살이에요?" (myeot sarieyo? — How old are you?) uses 살, and you respond with Native Korean numbers: "스물다섯 살이에요" (seumuldaseot sarieyo — I am 25 years old). In formal documents, medical forms, and news reports, 세 (se) with Sino-Korean numbers is standard. Age is culturally significant in Korean because it determines the speech level and social dynamics between people, which connects directly to understanding Korean honorifics.

Dates: Months, Days, and Years

Dates in Korean use Sino-Korean numbers exclusively. The order is year-month-day, which is the standard East Asian date format:

Year: 이천이십육 년 (icheonisimnyuk nyeon — 2026). The counter for year is 년 (nyeon).
Month: 삼월 (samwol — March). The counter for month is 월 (wol). January through December are simply 일월 through 십이월.
Day: 십삼일 (sipsamil — the 13th). The counter for day is 일 (il).

Full date example: 2026년 3월 13일 is 이천이십육 년 삼월 십삼일 (icheonisimnyuk nyeon samwol sipsamil). In casual speech, Koreans often just say the month and day: 삼월 십삼일 (samwol sipsamil — March 13th). Days of the week use their own vocabulary (월요일 woryoil — Monday, 화요일 hwayoil — Tuesday, etc.), which is separate from the number systems.

Quick Reference: Which System to Use

Tips for Mastering Korean Numbers

1. Practice in real-world contexts. Do not just memorize number lists. Practice ordering coffee (커피 두 잔 주세요, keopi du jan juseyo — two cups of coffee, please), reading prices at Korean online stores, and telling time throughout the day.

2. Use spaced repetition. Numbers need to be automatic — you should not have to pause and translate in your head. A spaced repetition system trains this automaticity by testing you at optimal intervals.

3. Master the shortened forms first. The 한/두/세/네 shortened forms before counters are the most commonly used number forms in daily Korean. Learn these before the full forms.

4. Practice the 만 grouping for money. Convert English prices to Korean 만 units daily. How much is $100 in won? About 십삼만 원 (simsamman won — 130,000 won). This mental conversion gets easier with practice.

5. Learn numbers with their counters. Never learn a counter in isolation. Always practice it as a unit: "한 잔, 두 잔, 세 잔..." (han jan, du jan, se jan...). This builds the muscle memory of pairing Native Korean numbers with specific counters. If you are preparing for the TOPIK, check out our TOPIK Level 1 study guide for a structured approach to building these foundations.