Korean Numbers: Why Learning the Two Number Systems Will Break Your Brain (Then Make Perfect Sense)

Look, I'm not going to sugarcoat it—learning numbers in Korean is annoying at first. You're sitting there trying to count in Korean, you've memorized 하나 (hana) for "one," and then someone asks for the price and suddenly it's 일 (il). What the hell?

Here's the thing though: once you understand why Korean has two number systems and when to use each number system, it actually becomes pretty straightforward. The problem is that most Korean learning resources either dump both the Sino-Korean number system and native Korean number system on you at once without context, or they try to make it seem simpler than it is.

Let me give you the real story about Korean numbers and how to actually master them.

The Actual Situation with Numbers in Korean

The Korean language has two sets of numbers you need to learn:

Why both? Because when Chinese characters (Hanja) came to Korea over a thousand years ago through the Chinese language, Koreans kept their native Korean number words for counting everyday things but adopted the Sino-Korean system for more formal contexts. Both stuck around, and now you need to learn how to use each one.

The good news? Each number system has specific jobs. You won't randomly pick the wrong one if you know the rules for when to use Korean numbers properly.

Sino-Korean Numbers: The Money/Date/Official Stuff

Start with Sino-Korean numbers. Seriously. The Sino-Korean counting system is easier for pronunciation and you'll use Sino-Korean numbers way more often than native Korean numbers in daily life.

The basic numbers 1 to 10 in Sino-Korean:

These Korean numbers 1-10 in Sino-Korean are the foundation. Once you master these basic numbers, building bigger numbers using the Sino-Korean system is dead simple.

Want to count up to 100? Just combine these basic numbers 1 to 10 with the numeral for tens. 11? Say 십일 (sip-il) - literally "ten-one." 23? 이십삼 (i-sip-sam) - "two-ten-three." Numbers from 1 to 99 follow this same pattern.

When to use Sino-Korean numbers:

Basically, if it's official, measured, or involves counting in formal ways, use the Sino-Korean number system. This is the Korean number system that dominates most of the Korean language.

Large Numbers in Korean: The 만 (10,000) Thing

Here's where the Korean number system gets weird for English speakers. Instead of counting in thousands, Korean counts in units of 10,000 called 만 (man).

So one million isn't "one thousand thousands"—it's 백만 (100 × 10,000). Your brain has to flip how you think about large numbers using this system.

Why does learning the numbers this way matter? Korean currency. The exchange rate is roughly 1,000 won to 1 dollar. That means a $100 coat is 십만원 (100,000 won). A flight to Seoul? 백만원 (1,000,000 won). You need to get comfortable with these larger numbers in Korean fast.

The key building blocks for numbers using Sino-Korean:

To say 35,000 using Sino-Korean: 삼만오천 (sam-man-o-cheon) - "three ten-thousands five thousands."

Numbers for 100, 1,000, and beyond follow logical patterns once you understand the 만 system. The Korean number 100 is just 백, number 1000 is 천, and you combine them to build any large numbers in Korean.

Native Korean Numbers: For Counting Real Stuff

Native Korean numbers only go to 99. Anything past the number 99, you switch to using Sino-Korean numbers.

Basic Korean numbers 1 to 10 (Native system):

These native Korean number words are trickier for pronunciation than Sino-Korean numerals. More syllables, weirder sounds. But you use native numbers less frequently, so it balances out.

The annoying part about native vs Sino: Tens don't follow a pattern in the native Korean system. You have to memorize these Korean words:

Making other numbers is easy though. 35? Just say 서른다섯 (seoreun-daseot) - "thirty-five."

When to use native Korean numbers:

If you're physically counting objects or talking about quantities of stuff, use the native Korean number system.

Korean Counters: The Extra Layer

Korean has counter words like Japanese does. You can't just say "three apples"—you need Korean counters to count properly.

The most common counter is 개 (gae), which works for most things. So "three apples" uses native Korean: 사과 세 개 (sagwa se gae).

Here's the catch: when you use native Korean numbers with counters, numbers 1-4 and 20 change form:

So "one apple" isn't 사과 하나 개, it's 사과 한 개. These contractions are essential for learning Korean counters properly.

Other Korean counters you'll need:

Don't worry about memorizing dozens of counters. Start with 개 and 명 as your basic Korean foundation.

Telling Time in Korean: Where Both Number Systems Collide

Here's where learning numbers gets genuinely weird. When you count time in Korean, you use both the Sino-Korean and native Korean number systems at once.

Hours = Native Korean numbers Minutes = Sino-Korean numbers

So 2:30 is 두 시 삼십 분 (du si samsip bun) - "two (native) o'clock thirty (Sino) minutes."

The structure for time in Korean: Hour (Native Korean) + 시 + Minute (Sino-Korean) + 분

Examples of counting time:

This is one of those things about the two Korean number systems where you just drill until it's automatic. There's no shortcut to mastering these Korean numbers in context.

Korean Ordinal Numbers and Age

Quick note about Korean ordinal numbers and age counting: You might hear about "Korean age" where everyone is born as 1 year old.

As of June 2023, South Korea officially ditched this traditional counting system. They now use international age (만 나이) for everything legal. Some people still use it casually, but if you're learning Korean now, you can mostly ignore Korean age unless reading older content.

For Korean ordinal numbers (first, second, third), you use native Korean with 번째 (beonjjae): 첫 번째 (first), 두 번째 (second), 세 번째 (third).

The Actual Learning Strategy for Korean Numbers

Here's what works for learning the numbers:

Week 1: Master Sino-Korean numbers 1-10, then count to 100. Numbers using Sino-Korean follow predictable patterns. Drill these basic numbers until you can say numbers without thinking.

Week 2: Learn native Korean numbers 1 to 10 and the basic Korean tens (20, 30, 40...). Practice native vs Sino switching.

Week 3: Add Korean counters. Start with 개, 명, and 병. Practice how native Korean number words contract with counters (한, 두, 세, 네).

Week 4: Time in Korean. Hours in native Korean, minutes in Sino-Korean. Use numbers in real sentences.

Don't try learning numbers in Korean all at once. Your brain can't handle memorizing two complete number systems simultaneously.

The key to learning Korean numbers? You need to hear how Korean numbers are used—prices in shops, times in shows, quantities in conversations. If you've already learned Hangul (the Korean alphabet), you're ready to pick up how Korean numbers work naturally from real content instead of just memorizing lists.

How to Master Korean Numbers from Real Content

The frustrating thing about learning numbers from textbooks is they give you lists of Korean words and phrases without context. You memorize 하나, 둘, 셋 in Hangul, but then you watch a Korean show and someone says 두 개 and you're confused about why 둘 became 두.

This is where learning from actual online Korean content makes a huge difference. When you see Korean numbers and how the Sino-Korean counting system works in real situations—someone ordering 아이스 아메리카노 두 잔 (two iced Americanos), a character checking time as 세 시 (3 o'clock), prices listed as 만 원 increments—your brain connects the patterns automatically.

You don't have to consciously think "okay, this uses native Korean with the counter 개 so 둘 contracts to 두." You just know because you've seen it used for counting a hundred times.

The problem is most Korean learners don't get enough exposure to how the rest of the numbers actually work early enough. They spend months drilling charts without hearing Korean numbers in natural speech. Then when they encounter phone numbers in Korean or need to say numbers quickly, nothing sounds familiar.

Understanding basic Korean grammar helps too, but honestly? Numbers are quite simple once you get raw exposure to how both number systems are used.

If you want to actually get comfortable with Korean numbers without making flashcards for every possible numeral combination, Migaku's browser extension lets you learn them the way they're actually used. Watch Korean shows and when you see prices, times, or quantities, you can instantly look up what you're hearing and add it to your spaced repetition deck.

You'll learn how to use Sino-Korean for phone numbers naturally, understand when native vs Sino-Korean applies, and pick up Korean counters as they appear in real sentences. The context sticks with you way better than drilling "하나, 둘, 셋" or "일, 이, 삼" in isolation with Hanja and Hangul charts.

Same thing with the mobile app—you can listen to Korean podcasts or audiobooks and hear how native speakers actually say numbers using both systems in conversation. You'll pick up on the rhythm of Sino-Korean phone numbers, the way people naturally say prices using 만, the casual way ages get mentioned. It's all there in real Korean content, and Migaku just makes it possible to capture and review that stuff efficiently.

Plus, the whole Korean counting system with counters makes way more sense when you see it in actual sentences. Instead of memorizing "개 is for things, 명 is for people," you just see 사과 세 개 show up in a recipe video and understand how to use Korean numbers with counters.

There's a 10-day free trial if you want to see how much faster the two Korean number systems stick when you're learning them from actual Korean instead of pronunciation charts.