Korean Number Converter

Type any number and get both Korean readings — Sino-Korean for prices and dates, Native Korean for ages and counting. The converter also shows the counter form (한, 두, 세, 네, 스무) when the cardinal changes before a counter.

This is a Stage 1–2 tool from the Korean TokTok curriculum — the free path from Hangul (Stage 1) to TOPIK 6급 (Stage 4). Korean numbers are introduced in Stage 1 and consolidated in Stage 2 (TOPIK 1–2급) alongside particles and verb conjugation.

When to use each system

The simplest rule: if you would write the number with a digit on a Korean form (price, date, address, phone), you read it Sino-Korean. If you would naturally count it on your fingers (people, books, animals, ages, hours of the day), you read it Native Korean.

One famous trap is 시간 — Korean uses Native for the hour (한 시) but Sino for the minute (삼십 분) on the same clock. So 1:30 is read 한 시 삼십 분. The hour is something you “experience” — Native — and the minute is an abstract dial reading — Sino. Korean speakers do not consciously switch; it is just baked into the words.

Beyond 100, you do not have a choice — Native Korean stops at 99, and everything larger is Sino. Beyond 10,000, the digit grouping changes: Korean groups by 4s using 만, 억, 조. So 십만 is “ten ten-thousands” (= 100,000), not “one hundred thousand”. This is the single biggest stumbling block for English-speaking learners.

Frequently asked questions

What is the difference between Sino-Korean and Native Korean numbers?

Korean has two parallel number systems. Sino-Korean (한자어 — 일, 이, 삼…) is borrowed from Chinese and is used for "abstract" numbers — prices, phone numbers, dates, addresses, math. Native Korean (고유어 — 하나, 둘, 셋…) is the original Korean system and is used for "concrete" things you can count — ages, hours of the day, and most counters. Native Korean only goes up to 99; for anything larger, both systems converge on Sino-Korean.

Which number system do I use for my age?

Native Korean. "21 years old" is 스물한 살 (seumul-han sal), not 이십일 살. The same is true for hours of the day (한 시 = 1 o'clock, not 일 시) and most general counters like 명 (people), 개 (things), 권 (books). Use Sino-Korean only for the minute (3시 30분 — 분 is Sino), the year and date (2026년 5월 1일), and prices (15,000원).

Why is "twenty" different when used as a counter? (스물 vs 스무)

Native Korean numbers 1, 2, 3, 4, and 20 have a special "attributive" form used directly before a counter: 하나→한, 둘→두, 셋→세, 넷→네, 스물→스무. So "two people" is 두 명 (not 둘 명), and "twenty years old" is 스무 살 (not 스물 살). The converter shows this counter form whenever it differs from the cardinal.

How do I read large numbers in Korean?

Korean groups digits in 4s, not 3s like English. The big units are 만 (10,000), 억 (100,000,000), and 조 (1 trillion). So 50,000 is 오만 (5 × 10,000), and 1,000,000 is 백만 (100 × 10,000), not "one million". Once you internalize the 4-digit grouping, large numbers feel natural — but it takes English speakers some practice.

Is the converter accurate for very large numbers?

Yes — it supports values up to 9,999조 (about 10¹⁶). The reading rules are deterministic, so the output is exact for every integer in that range. It runs entirely in your browser — no number you type is sent to a server.

Sino-Korean (한자어)

Native Korean (고유어)

With common counters