Ask a friend in Seoul how big their apartment is, and you will almost never hear a number of square meters. You will hear something like “thirty-four pyeong.”
Then look at the official listing for the same apartment. It says 84 m².
Here’s the puzzle: 84 square meters is only about 25 pyeong. So how can one apartment be 34 pyeong and 25 pyeong at the same time? And why does a country that officially switched to the metric system decades ago still talk about homes in an old unit most foreigners have never heard of?
The answer is a small story about history, habit, and the way Koreans buy homes.
What exactly is a pyeong?
A pyeong (평) is a square, one kan (간) on each side. A kan was a traditional building measure, the space between two posts in a wooden house, equal to six Korean feet. So one pyeong is 6 × 6 = 36 square Korean feet.
In metric terms, one pyeong is exactly 400/121 square meters, or about 3.3058 m². That is a little bigger than a queen-size bed. Most Koreans simply round it to 3.3.
That oddly precise number has a history. During the Japanese colonial period, Korea’s traditional units were tied to Japan’s, and the pyeong became exactly the same size as the Japanese tsubo. In Japan, a tsubo is often described as the space of two tatami mats. The two countries still share the same unit today, under different names.
The quick conversions:
- Pyeong to square meters: multiply by 3.3058
- Square meters to pyeong: multiply by 0.3025 (or divide by 3.3058)
The unit Korea tried to ban
Officially, South Korea gave up the pyeong a long time ago. The metric system became the legal standard in 1961, and the pyeong has been an unofficial unit ever since.
For more than 40 years, almost nobody noticed. Builders, real estate agents and newspapers kept using pyeong, because that is what buyers understood.
So in July 2007 the government got serious. Using pyeong in commercial transactions, such as ads, sales brochures and model homes, was no longer allowed. Apartment areas had to be written in square meters. Even the popular way of quoting prices, “so many won per pyeong,” had to change. News reports from that summer showed the awkward result: a price of 7.75 million won per pyeong became “2.28 million won per m².”
The rule worked on paper. Open any Korean listing today and the official area is in square meters.
But it didn’t change how people talk.
Why the pyeong survived
Habit is hard to legislate
For generations of Koreans, pyeong is simply how a home feels. “A 20-pyeong place” means a small apartment for a young couple. “Thirties” (30평대) means a family apartment. People compare homes, set goals and judge prices in those terms, and they learned them long before 2007.
The unit even hides inside the metric numbers. Korean news still quotes apartment prices “per 3.3 m².” That is a pyeong wearing a metric disguise.
The 34-pyeong puzzle
Now back to our apartment that is 84 m² and 34 pyeong at the same time.
Korean listings use more than one kind of area:
| Korean term | What it includes | Our example |
|---|---|---|
| 전용면적 (exclusive area) | The space inside your front door: rooms, kitchen, bathrooms | 84 m² ≈ 25 pyeong |
| 공급면적 (supply area) | Exclusive area plus your share of the building’s halls, stairs and elevators | 114 m² ≈ 34 pyeong |
The official number in square meters is the exclusive area. The number people say out loud, “34 pyeong,” is the supply area. Both are true. They just measure different things.
Balconies are another twist. They usually aren’t counted in either number, which is why many Korean apartments feel bigger than their official size.
Why 84 m² is “the nation’s size”
One of the most popular apartment sizes in Korea is 84 m², so popular that it has a nickname: 국민평형, “the national size.”
That also comes from the pyeong. In 1973, Korea’s housing plan assumed a family needed about 5 pyeong per person. For a family of five, that is 25 pyeong, about 82.6 m². The government set the standard for “national housing” at 85 m² of exclusive area, and builders designed right up to the line: 84 m².
The 85 m² line still matters today for taxes and for Korea’s apartment lottery system, so builders keep using it. The metric number on the listing is really a pyeong-era decision in disguise.
How to read a Korean listing
If you are renting or buying in Korea, or just curious, here are the common sizes side by side. The “people say” column uses supply area, which is how most Koreans describe a home. Exact supply areas vary a little by building.
| Listing says (exclusive) | Exclusive area in pyeong | People say (supply) |
|---|---|---|
| 59 m² | about 18 pyeong | “25 pyeong” |
| 74 m² | about 22 pyeong | “30 pyeong” |
| 84 m² | about 25 pyeong | “34 pyeong” |
| 114 m² | about 34 pyeong | “43 pyeong” |
Three tips:
- When someone says a pyeong number, ask which area they mean. For apartments it is usually supply area. For offices and stores it can be different.
- Compare prices by exclusive area. That is the space you actually live in.
- Don’t forget the balcony. Two apartments with the same official size can feel very different.
Want to check a number yourself? Our Pyeong to Square Meters Converter turns pyeong into square meters and back, instantly.
A small unit with a long memory
The pyeong is a good reminder that measurements are not just numbers. They carry history. A unit born from the space between two wooden posts, reshaped in the colonial era, and banned twice by law still decides how Koreans picture a home.
So the next time a Korean friend tells you their apartment is “34 pyeong,” you’ll know three things: it’s about 84 m² inside, it’s probably the nation’s favorite size, and the old unit is still doing its job.
Sources
- Pyeong, Wikipedia: definition (400/121 m²), the 1961 metric standard and the July 2007 ban on commercial use
- “‘3.3㎡(1평)당’ 단위 못쓴다”, 이투데이, August 31, 2007: the switch from per-pyeong to per-m² prices and the price example
- 국민평형이라는 전용면적 84㎡는 왜 34평형일까요?, KB Think: exclusive vs. supply area, the conversion table and the 1973 origin of the 85 m² standard