Twin XL (US) in a 3600 mm room — 1318 mm each side

Same room, other beds

A Korean Queen is 150 × 200 cm and an American Queen 152.4 × 203.2 — close enough. But at King the two part ways: 160 cm against 193, a gap of 33. An American King is wider even than a Korean Super King at 180. That is why matching names when buying bedding abroad leaves you with sheets that do not fit.

What you hit is the walkway

A room can be roomy on paper and still leave nowhere to walk once the bed is in. Squeezing past sideways needs about 60 cm on one side, and opening a wardrobe or a drawer needs more. So this table subtracts the bed’s width from the room’s short wall and halves what is left — push the bed against a wall and you give up one side but double the other.

Two people get less than a single bed each

Two people on a Korean Queen at 150 cm get 75 cm each. A single bed is 100 cm, so each sleeper has 25 cm less than a single. Even a King at 160 cm gives 80 cm apiece. The numbers make it plain: no matter how grand the name, sharing does not buy you a single bed’s width each.

Nearby room widths

Same bed, other rooms

The standard does not use these names

The Korean national standard fixes ranges for a mattress’s width and length but never uses words like “single”, “super single” or “queen”. Makers therefore agree closely from single up to queen, and diverge above king, where each company picks its own figures. The Korean numbers here are the trade’s common usage, not a legal size.

How to read this

• Walkway per side = (short wall − bed width) ÷ 2.
• Squeezing past needs about 60 cm on one side.
• Against a wall you lose one side but double the other.
• These are mattress dimensions; a frame adds 5–15 cm.