Korean number converter

Korea has two whole sets of numbers

Of all the things I've run into while learning Korean, the two number systems were the one that made me laugh out loud at my own confusion. Just when you've memorized how to count, you find out there's a second set of numbers, and they're not interchangeable. I promise it makes sense once it clicks, and a converter like the one on this page is a lovely way to check yourself while it does.

The two systems are Sino-Korean (numbers borrowed long ago from Chinese) and native Korean (the original homegrown numbers). Both are used constantly in everyday life — the trick is knowing which situation calls for which.

Sino-Korean vs native Korean

Here's the simplest way I keep them straight:

• Sino-Korean (일, 이, 삼, 사…) goes all the way up effortlessly and is what you use for anything "big system" — dates, money, phone numbers, addresses, minutes, and counting above 99.
• Native Korean (하나, 둘, 셋, 넷…) is for the human-scale, hands-on stuff — hours on the clock, your age, and counting physical things from 1 to 99.

One mercy worth knowing: native Korean numbers traditionally only go up to 99, and even those get used less at the high end in modern speech. So once you're counting past a hundred, you're firmly in Sino-Korean territory and you can stop worrying about which set to reach for.

When to use each one

Let me make this concrete, because rules in the abstract never stuck for me. Here's the everyday breakdown:

• Dates (year, month, day): Sino-Korean.
• Money / prices: Sino-Korean.
• Minutes and seconds: Sino-Korean.
• Counting anything above 99: Sino-Korean.
• The hour on a clock: native Korean.
• Someone's age: native Korean.
• Counting objects, people, cups, books (1–99): native Korean.

The one that delights me every time is telling time, because it uses both at once. "3:20" is native Korean for the hour (세 시) and Sino-Korean for the minutes (이십 분). One little phrase, both systems, working together.

How counters tell you which set to use

This was the piece that finally made it intuitive for me. Korean uses counter words — little measure words that come after a number, similar to saying "two sheets of paper" or "three cups of coffee" in English. The counter you're using is a strong signal for which number system to pick.

Counters used for everyday counting of things — 개 (general items), 명 (people), 마리 (animals), 잔 (cups/glasses) — pair with native Korean numbers. Counters tied to the "big system" like 원 (money), 분 (minutes), 년 (year), and 번 (number in a sequence) pair with Sino-Korean. Once you start noticing the counter, the right number set often picks itself.

Common learner mistakes

Mistakes I've made and seen, so you can skip them:

• Using Sino-Korean for your age. Age is native Korean (until you get into very large or formal contexts). Saying your age with the wrong set is a classic giveaway.
• Mixing up hours and minutes. Remember: hour native, minute Sino. Don't let one bleed into the other.
• Forgetting that native numbers change shape before a counter. 하나 becomes 한, 둘 becomes 두, 셋 becomes 세 right before a counter word. So it's 한 개, not 하나 개.
• Reaching for native numbers past 99. Up there, it's Sino-Korean all the way.

Which Korean numbers should I learn first?

I'd start with native Korean 1 through 10 plus the common counters, because that's what you'll use out loud the most early on — ordering, counting, telling someone your age. Then learn Sino-Korean alongside it for dates, prices, and time, since those come up the instant you buy anything or make a plan. Learning them in pairs (the same quantity in both systems) helped me feel the difference instead of just memorizing two cold lists.

Be patient with yourself here — this is genuinely one of the trickier early hurdles, and getting it wrong is part of getting it right. If you want to count along with me, visit my Korean learning page, then use the converter above to double-check your numbers in both systems.