🏠 Pyeong Calculator – Convert Pyeong ↔ m² and Break Down Apartment Area
1 pyeong is exactly 400/121 m² — 3.3057851 m² — and 1 m² is exactly 0.3025 pyeong. This calculator converts both directions instantly, then goes further: enter any two of supply area, exclusive area and exclusive ratio, and it derives the third plus the residential common area. Everything runs in your browser, so nothing is uploaded and it works offline.
A pyeong calculator converts between pyeong (평, a traditional East Asian area unit equal to 400/121 m²) and square meters, and splits an apartment's floor area into supply, exclusive and common area.
Quick convert
1 pyeong = 400/121 m² = 3.3057851 m² (exact). 1 m² = 0.3025 pyeong.
Apartment area breakdown
Enter any TWO of supply area / exclusive area / exclusive ratio — the third is derived.
Common apartment sizes
| Size (평형, supply) | Supply m² | Exclusive m² (75%) | Exclusive 평 |
|---|
Exclusive area assumes a 75% ratio — a typical apartment figure, not a legal constant. Always check the actual figure on the listing.
Private by design. This tool runs entirely in your browser — nothing you enter is uploaded or stored, and it works offline.
About
Korean property listings mix two systems. Since 2007 the legal notation has been square meters of exclusive area (전용면적), but people still talk in pyeong of supply area (공급면적) — which is why a "34-pyeong" apartment is usually listed as 84.9 m². This tool holds both at once.
The area terms nest like this. Exclusive area (전용면적) is the space inside your front door — rooms, living room, kitchen, bathroom. Residential common area (주거공용면적) is the shared structure of the building: stairs, corridors, elevators, entrance halls. Add them together and you get supply area (공급면적), the number traditionally quoted as a pyeong size. Add other common area (기타공용면적) — the management office, security post, parking — and you get contract area (계약면적). Balconies are separate again: they are service area (서비스면적) and belong to none of the above, which is why an expanded balcony makes a flat feel larger than its paperwork suggests.
The exclusive ratio (전용률) is exclusive area divided by supply area. Korean apartments typically land between 70% and 80%. Officetels look far lower — often 30–40% — but that is partly an accounting artifact: apartments quote supply area as the sales area while officetels quote contract area, so the same building measured two ways produces two very different percentages.
One deliberate limitation: with only one number, this calculator refuses to guess. If you know just the supply area, the exclusive area cannot be derived, because the ratio differs from complex to complex. Assuming a "typical 75%" would produce a confident, plausible, wrong answer — so the tool says what it cannot do instead. Enter two values and it computes exactly.
How to use
- Quick convert: type a number, pick m² or pyeong, and read the converted value. Press Copy to take it.
- For the breakdown, first choose whether you are typing in m² or pyeong.
- Fill in any TWO of supply area, exclusive area and exclusive ratio. The third is derived automatically, along with the residential common area.
- Optionally add the balcony to get usable area, or other common area to get contract area (useful for officetels).
- Every row is shown in both m² and pyeong. Use Copy result to paste the whole breakdown elsewhere.
FAQ
- How many square meters is 1 pyeong?
- Exactly 400/121 m², which is 3.3057851… m². It comes from 6 ja × 6 ja, where 1 ja is 10/33 m. Going the other way, 1 m² is exactly 0.3025 pyeong. This calculator uses the exact fraction rather than a rounded 3.3058, so large areas stay accurate.
- I know it's a 34-pyeong apartment. What is the exclusive area?
- It cannot be determined from that alone. 34 pyeong is supply area (about 112.4 m²), and the exclusive area depends on the exclusive ratio, which differs by complex. At 75% it would be about 84.3 m²; at 70% about 78.7 m². Find the actual exclusive area on the listing or the register, then enter both numbers here.
- What is the difference between supply area and exclusive area?
- Exclusive area is the space inside your unit — rooms, living room, kitchen, bathroom. Supply area is that plus your share of the building's residential common space: stairs, corridors, elevators, entrance halls. Supply area is the bigger number and is what "34 pyeong" traditionally refers to.
- What exclusive ratio is normal?
- Korean apartments are typically 70–80%. A higher ratio means more of what you pay for is inside your own front door. Officetels commonly show 30–40%, but part of that gap is measurement convention rather than wasted space — see the next question.
- Why is an officetel's exclusive ratio so much lower?
- Apartments quote supply area (exclusive + residential common) as the sales area, while officetels quote contract area (supply + other common, including parking and management facilities). Dividing by a bigger denominator produces a smaller percentage, so the two numbers are not directly comparable. Compare exclusive area in m² instead.
- Why isn't the balcony included in the area?
- A balcony is service area (서비스면적) and is excluded from exclusive, supply and contract area by law. That is why two units with the same registered area can feel very different once one has an expanded balcony. Enter the balcony in the optional field to see usable area — exclusive plus balcony.
- How many pyeong is the 85 m² national housing size?
- 85 m² of exclusive area is 25.71 pyeong. It is usually marketed as a "34-pyeong" unit because that figure refers to supply area at roughly a 75% exclusive ratio. The same home therefore carries two different pyeong numbers depending on which area is meant — a frequent source of confusion.
- Is my data uploaded anywhere?
- No. Every calculation runs in JavaScript inside your browser. Nothing is sent to a server, there is no login, and once the page has loaded it keeps working offline.