Korean Numbers: Big Numbers (만, 억, 조)
Korean groups large numbers by 10,000 (만), not 1,000. This is the biggest mental shift for English speakers. 1 million = 백만 (100 만). 1 billion = 십억...
Category: Korean Numbers
The Rule
Korean groups large numbers by 10,000 (만), not 1,000. This is the biggest mental shift for English speakers. 1 million = 백만 (100 만). 1 billion = 십억 (10 억). Korean has TWO completely separate number systems — Native Korean (하나, 둘, 셋) and Sino-Korean (일, 이, 삼). English speakers must learn WHEN to use which system, because mixing them up is a common and noticeable mistake. Korean has two complete number systems — native Korean (고유어 수사, goyueo susa) and Sino-Korean (한자어 수사, hanja-eo susa) — and knowing which to use in each situation is one of the most practical challenges for learners. Unlike most languages that have one counting system, Korean requires you to switch between systems depending on what you are counting, measuring, or describing. This dual system can seem overwhelming at first, but the rules for which system to use are actually quite consistent once learned. Native Korean numbers are used for counting things with counters, telling hours, and expressing ages in casual speech. Sino-Korean numbers are used for dates, phone numbers, addresses, money, minutes, and formal/written ages. Some contexts accept both systems with subtle differences in nuance or formality.
The Two Number Systems Explained
The native Korean number system has roots in the original Korean language and goes from one to ninety-nine, though numbers above the low teens are increasingly rare in modern usage. 하나 (hana, 1), 둘 (dul, 2), 셋 (set, 3), 넷 (net, 4), 다섯 (daseot, 5), 여섯 (yeoseot, 6), 일곱 (ilgop, 7), 여덟 (yeodeol, 8), 아홉 (ahop, 9), 열 (yeol, 10). For 11-19, combine 열 with single digits: 열하나 (yeolhana, 11), 열둘 (yeoldul, 12). Tens use special forms: 스물 (seumul, 20), 서른 (seoreun, 30), 마흔 (maheun, 40), 쉰 (swin, 50), 예순 (yesun, 60), 일흔 (ilheun, 70), 여든 (yeodeun, 80), 아흔 (aheun, 90). The Sino-Korean system, derived from Chinese, covers all numbers and is structurally simpler: 일 (il, 1), 이 (i, 2), 삼 (sam, 3), 사 (sa, 4), 오 (o, 5), 육 (yuk, 6), 칠 (chil, 7), 팔 (pal, 8), 구 (gu, 9), 십 (sip, 10), 백 (baek, 100), 천 (cheon, 1000), 만 (man, 10000).
When to Use Which System
The choice between native Korean and Sino-Korean numbers follows specific rules that must be memorized by context. Use NATIVE Korean for: hours in time (세 시, se si, '3 o'clock'), counting objects with counters (사과 세 개, sagwa se gae, '3 apples'), age in casual speech (스물다섯 살, seumuldaseot sal, '25 years old'), counting people casually (세 명, se myeong, '3 people'). Use SINO-Korean for: minutes and seconds (삼십 분, samsip bun, '30 minutes'), dates and months (삼월, samwol, March; 십오일, sibo-il, the 15th), phone numbers (공일공, gong-il-gong, 010), money (삼천 원, samcheon won, '3000 won'), addresses and room numbers, floors of buildings (삼층, samcheung, '3rd floor'), years (이천이십육년, icheonisimnyungnyeon, '2026'). Some contexts use BOTH: age can use either system, with Sino-Korean being more formal (이십오 세, isibo se). Knowing these rules prevents the most common number-related errors in Korean.
Numbers with Counters (Classifiers)
Korean uses counter words (분류사, bullyusa) between numbers and nouns — similar to English 'two sheets of paper' or 'three cups of coffee,' but applied to virtually everything. The number system used with each counter must be memorized. Common counters using NATIVE Korean numbers: 개 (gae, general objects), 명 (myeong, people polite), 사람 (saram, people casual), 마리 (mari, animals), 권 (gwon, books), 잔 (jan, cups/glasses), 병 (byeong, bottles), 장 (jang, flat objects/sheets), 대 (dae, vehicles/machines), 벌 (beol, clothing sets), 그루 (geuru, trees), 송이 (songi, flowers/bunches), 켤레 (kyeolle, pairs of shoes/socks). Important: native Korean numbers 1-4 change form before counters — 하나→한 (han), 둘→두 (du), 셋→세 (se), 넷→네 (ne), 스물→스무 (seumu). So 'two cats' is 고양이 두 마리 (goyangi du mari). Mastering counters with correct number forms is essential for natural-sounding Korean.
Telling Time: The Mixed System
Korean time-telling uniquely combines both number systems in a single expression: native Korean for hours and Sino-Korean for minutes. 세 시 삼십 분 (se si samsip bun, '3:30') uses native 세 (se, 3) for the hour and Sino-Korean 삼십 (samsip, 30) for minutes. Hours use native Korean: 한 시 (han si, 1 o'clock), 두 시 (du si, 2), 세 시 (se si, 3), through 열두 시 (yeoldu si, 12). Minutes and seconds use Sino-Korean: 일 분 (il bun, 1 minute), 이십 분 (isip bun, 20 minutes), 삼십 초 (samsip cho, 30 seconds). A.M. is 오전 (ojeon) and P.M. is 오후 (ohu), placed before the time: 오후 세 시 (ohu se si, '3 PM'). 'Half past' can be expressed as 삼십 분 (samsip bun) or colloquially 반 (ban, 'half'): 세 시 반 (se si ban, '3:30'). This mixed system confuses many learners, but with daily practice telling the current time in Korean, it becomes automatic within a few weeks.
Money, Prices, and Shopping
Korean currency (원, won) uses the Sino-Korean number system exclusively. Understanding number expressions for money is essential for daily life in Korea. Basic price patterns: 천 원 (cheon won, 1,000 won), 오천 원 (ocheon won, 5,000 won), 만 원 (man won, 10,000 won), 오만 원 (oman won, 50,000 won). Korean groups large numbers by 만 (man, 10,000) rather than 'thousand' as in English. So 100,000 won is 십만 원 (simman won, literally 'ten ten-thousands'). Shopping phrases: 이거 얼마예요? (igeo eolmayeyo?, 'How much is this?'), 좀 깎아주세요 (jom kkakkajuseyo, 'Please give me a discount'), 너무 비싸요 (neomu bissayo, 'Too expensive'), 현금으로 할게요 (hyeongeumueuro halgeyo, 'I will pay cash'). Receipt is 영수증 (yeongsujeung). Tax-free shopping: 세금 환급 (segeum hwangeup, tax refund). Understanding prices quickly — hearing 삼만 오천 원 (samman ocheon won) and knowing it means 35,000 won — requires practice with mental arithmetic in the Korean number framework.
Dates, Birthdays, and Calendar Terms
Dates in Korean use the Sino-Korean system in year-month-day order (the opposite of American English). 이천이십육년 오월 육일 (icheonisimnyungnyeon owol yugil, May 6, 2026). Months are simply Sino-Korean number + 월 (wol, month): 일월 (irwol, January), 이월 (iwol, February), through 십이월 (sibiwol, December). Days use number + 일 (il, day): 일일 (iril, 1st), 이일 (iil, 2nd), through 삼십일일 (samsibilil, 31st). Days of the week: 월요일 (woryoil, Monday), 화요일 (hwayoil, Tuesday), 수요일 (suyoil, Wednesday), 목요일 (mogyoil, Thursday), 금요일 (geumyoil, Friday), 토요일 (toyoil, Saturday), 일요일 (iryoil, Sunday). Birthday is 생일 (saengil), and age can be stated as native Korean 스물다섯 살 (seumuldaseot sal, 25 years old) in casual speech or Sino-Korean 이십오 세 (isibo se) in formal contexts. Korea traditionally used a different age-counting system, but 만 나이 (man nai, international age) is now standard as of 2023 legal reform.
Phone Numbers and Addresses
Korean phone numbers and addresses use Sino-Korean numbers, but with specific reading conventions. Phone numbers are read digit by digit, with 0 pronounced as 공 (gong, 'zero') rather than 영 (yeong). A typical Korean mobile number 010-1234-5678 is read as 공일공-일이삼사-오육칠팔 (gong-il-gong il-i-sam-sa o-yuk-chil-pal). Hyphens are indicated by a brief pause. Address vocabulary: 시 (si, city), 구 (gu, district), 동 (dong, neighborhood), 로 (ro, road/street), 번지 (beonji, lot number), 층 (cheung, floor), 호 (ho, room/unit number). A Korean address reads from largest to smallest unit: 서울시 강남구 역삼동 123번지 (Seoul-si Gangnam-gu Yeoksam-dong 123-beonji). Apartment building and unit: 아파트 (apateu) 동 (dong, building) 호 (ho, unit). For example, 삼동 이백오호 (samdong ibaeko-ho, Building 3, Unit 205). Practicing reading phone numbers and addresses aloud builds fluency with Sino-Korean numbers in practical contexts.
Large Numbers and the 만 System
Korean groups large numbers in units of 만 (man, 10,000) rather than thousands, which requires a mental shift for English speakers. 만 (man, 10,000), 십만 (simman, 100,000), 백만 (baengman, 1,000,000), 천만 (cheonman, 10,000,000), 억 (eok, 100,000,000), 조 (jo, 1,000,000,000,000). So one million is 백만 (baengman, 'hundred ten-thousands'). Seoul's population of about 10 million is 천만 (cheonman, 'thousand ten-thousands'). Korea's GDP in trillions of won uses 조 (jo). This four-digit grouping system means that commas in Korean numbers fall in different places mentally than in English. Practice converting between systems: $50,000 = 오만 달러 (oman dalleo). A 300,000,000 won apartment is 삼억 원 (sameok won). Reading Korean financial news or real estate listings provides excellent practice with large numbers. Many learners find it helpful to memorize the conversion table: 만=10K, 십만=100K, 백만=1M, 천만=10M, 억=100M.
Practice Strategies for Number Fluency
Number fluency in Korean requires dedicated practice because the dual system and counter words create many potential confusion points. Here are proven strategies. Daily time practice: every time you check the clock, say the time in Korean using the mixed system. Price practice: when shopping (in Korea or online), read all prices in Korean. Phone number practice: save friends' contacts with Korean number readings. Date practice: write your daily journal date in Korean. Random number drills: have a friend show random numbers for you to read aloud, alternating between native and Sino-Korean as appropriate. Counter practice: count objects around you using appropriate counters — three books on the shelf is 책 세 권 (chaek se gwon). Speed drills: set a timer and read as many numbers as possible in one minute. Math in Korean: try simple addition and subtraction using Korean numbers. Age practice: calculate family members' ages using both number systems. Consistent daily practice of even five minutes transforms number anxiety into number confidence within a month.
Examples
인구가 오천만 명이에요. — inguga ocheonman myeongieyo. — The population is 50 million.
그 건물이 십억 원이에요. — geu geonmuri sipeok wonieyo. — That building is 1 billion won.
국가 예산이 육백조 원이에요. — gukga yesani yukbaekjo wonieyo. — The national budget is 600 trillion won.
하나, 둘, 셋, 넷, 다섯 — hana, dul, set, net, daseot — 1, 2, 3, 4, 5 (Native Korean)
일, 이, 삼, 사, 오 — il, i, sam, sa, o — 1, 2, 3, 4, 5 (Sino-Korean)
세 시 삼십 분 — se si samsip bun — 3:30
커피 두 잔 주세요 — keopi du jan juseyo — Two cups of coffee, please
이만 오천 원이에요 — iman ocheon wonieyo — It's 25,000 won
저는 스물다섯 살이에요 — jeoneun seumuldaseot sarieyo — I am 25 years old
공일공-이삼사오-육칠팔구 — gong-il-gong i-sam-sa-o yuk-chil-pal-gu — 010-2345-6789
Common Mistakes
Incorrect: Using the wrong number system → Correct: 인구가 오천만 명이에요.. Korean has two number systems. Big Numbers (만, 억, 조) requires specific number types.
Incorrect: Using Sino-Korean for hours (삼 시) → Correct: 세 시 (native Korean). Hours always use native Korean. 삼 시 is wrong — use 세 시 for 3 o'clock.
Incorrect: Using native Korean for minutes (셋 분) → Correct: 삼 분 (Sino-Korean). Minutes always use Sino-Korean. Use 삼 분 for 3 minutes.
Incorrect: Not shortening 하나→한 before counters → Correct: 한 개 (han gae). Native 1-4 and 20 shorten before counters: 하나→한, 둘→두, 셋→세, 넷→네.
Incorrect: Grouping large numbers by thousands → Correct: Group by 만 (10,000) — Korean style. 1,000,000 is 백만 (hundred ten-thousands). Korean groups by fours, not threes.
Incorrect: Using 영 for zero in phone numbers → Correct: Use 공 (gong) for phone numbers. Phone numbers use 공 for zero. 010 = 공일공.
Quiz
Which number system does "Big Numbers (만, 억, 조)" use?
Korean groups large numbers by 10,000 (만), not 1,000.
Which number system is used for hours?
Hours use native Korean: 한 시, 두 시, 세 시...
How do you say 25,000 won?
25,000 = 이만(20,000) 오천(5,000) 원.