한국어 — Numbers cheat sheet

The big picture

Korean has two complete number systems running in parallel. The native Korean set (하나, 둘, 셋…) is used for counting things, ages, and hours. The Sino-Korean set (일, 이, 삼…) is used for dates, money, addresses, minutes — and is the only option for any number 100 or above.

If you only remember one thing: both systems exist for 1–99. Once you cross 100, Sino-Korean takes over completely. Native Korean simply has no words past 아흔아홉 (99).

Zero to ten: both systems

Sino-Korean is borrowed from Chinese and uses the same characters under the hood (compare 십 sip to Mandarin 十 shí). Native Korean is unrelated — entirely Korean stems.

Sino-Korean

일, 이, 삼…

dates · money · addresses · 100+

영 / 공

yeong / gong

일

이

삼

sam

사

오

육

yuk

칠

chil

팔

pal

구

십

sip

Native Korean

하나, 둘, 셋…

counting things · age · hours

하나

hana

둘

dul

셋

set

넷

net

다섯

daseot

여섯

yeoseot

일곱

ilgop

여덟

yeodeol

아홉

ahop

열

yeol

Counter shortening on 1, 2, 3, 4. Before a measure word, native Korean numbers shrink: 하나 → 한, 둘 → 두, 셋 → 세, 넷 → 네. So "one item" is 한 개 (han gae), not 하나 개. This applies anywhere you're counting things — including ordinals (see section 05). 5+ doesn't change.

11 – 99: both systems

Sino-Korean tens are perfectly compositional: digit + 십. Native Korean tens are completely unique words — you have to memorize eight new lexical items (스물, 서른, 마흔…). This is where the two systems diverge most.

Sino-Korean

Tens: just multiply

all regular

십

sip

이십

i-sip

삼십

sam-sip

사십

sa-sip

오십

o-sip

육십

yuk-sip

칠십

chil-sip

팔십

pal-sip

구십

gu-sip

사십이

sa-sip-i

4 × 10 + 2 — same logic as Mandarin

Native Korean

Tens: eight unique words

memorize each one

열

yeol

스물

seumul

서른

seoreun

마흔

maheun

쉰

swin

예순

yesun

일흔

ilheun

여든

yeodeun

아흔

aheun

마흔둘

maheun-dul

unique tens word + native unit

아흔아홉

aheun-ahop

the highest native Korean number

100+: Sino only, group by 만

Past 99, only Sino-Korean. And here's the structural twist Korean shares with Mandarin: Sino-Korean groups by 10⁴, not by 10³. The next "big unit" after 천 (thousand) isn't million — it's 만 (10,000). So 1,000,000 is 백만, "hundred ten-thousands."

100

백

baek

200

이백

i-baek

500

오백

o-baek

1,000

천

cheon

2,000

이천

i-cheon

10⁴

10,000

만

man

100,000

십만

sim-man

"million"

1,000,000

백만

baek-man

10,000,000

천만

cheon-man

10⁸

100,000,000

억

eok

1,000,000,000

십억

sip-eok

52,610

오만 이천 육백 십

o-man i-cheon yuk-baek sip

5 × 만 + 2 × 천 + 6 × 백 + 10

No leading "one." Unlike Mandarin's yī bǎi (一百) for 100, Korean drops the "one" — it's just 백, not 일백. Same for 1,000 (천, not 일천) and 10,000 (만, not 일만). One sino-character does the whole job.

Mental commas every four digits. English thinks 1,000,000 (a million). Korean re-comma's it as 100,0000 — that's 백만 (100 × 만 = "hundred ten-thousands"). Same conversion exercise as Mandarin, with similar payoff once you internalize it.

Which system, when?

The biggest practical question for Korean learners. The rules below cover the most common contexts — but spoken Korean has wiggle room, and some situations mix the two systems within a single phrase (most famously, time).

Counting items 한 개, 두 개, 세 개 (one item, two items, three items) Native

Age 스물다섯 살 (25 years old) Native

Hours (time) 세 시 (3 o'clock) Native

Minutes (time) 오 분 (5 minutes) Sino

Dates 시월 십오일 (October 15) Sino

Money 오천 원 (5,000 won) Sino

Phone numbers 공일공 오공구사 (010-5094) Sino

Addresses 강남구 123번지 (Gangnam-gu, no. 123) Sino

Any number 100+ 백, 천, 만, 백만, 억 (forced Sino at this scale) Sino

Telling time is mixed. Hours use native, minutes use Sino. So 3:25 is 세 시 이십오 분 — native se (3) for the hour and Sino i-sip-o (25) for the minutes. It feels strange at first; it gets automatic.

Ordinals

The everyday pattern is native number + 번째 (beonjjae, "-th"). The one exception is first: 첫 번째 (cheot beonjjae), not 한 번째. Numbers 2-4 use their shortened counter forms.

special

1st

첫 번째

cheot beonjjae

→ 두

2nd

두 번째

du beonjjae

→ 세

3rd

세 번째

se beonjjae

→ 네

4th

네 번째

ne beonjjae

5th

다섯 번째

daseot beonjjae

6th

여섯 번째

yeoseot beonjjae

10th

열 번째

yeol beonjjae

25th

스물다섯 번째

seumul-daseot beonjjae

The formal alternative: 제 + Sino number. In written or formal contexts (book chapters, official events), use the prefix 제 with a Sino-Korean number instead: 제일 (first), 제이 (second), 제삼 (third). You'll see this on textbook chapters (제이장 = "Chapter 2") and event names. For everyday conversation, stick with 번째.

Things to remember

Five rules that will save you from the most common mistakes.

Two systems, parallel. 하나 and 일 both mean "one." Native counts things and ages; Sino runs everything official.

Native stops at 99. Anything 100 or above is Sino-Korean. There simply isn't a native word for "hundred."

1-4 shrink before counters. 하나 → 한, 둘 → 두, 셋 → 세, 넷 → 네. 한 개 for "one item," 두 시 for "two o'clock." The base form only appears when standing alone.

Big-unit grouping is by 10⁴, not 10³. 만 (ten-thousand) is the next big unit after 천, and 억 is 10⁸. "One million" in Korean is 백만 — "hundred ten-thousands."

Time mixes both. Hours = native (세 시), minutes = Sino (오 분). Same clock face, two different number systems. It's the most useful rule to internalize early.

Drill it

Reading is one thing.
Hearing it at speed is another.

The companion iOS app generates random numbers in your chosen range and reads them aloud in Korean. Five minutes a day.

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Numbers in한국어 Korean