The layout code: 1R, 1K, 1DK, 1LDK

The code at the start of a listing describes the layout. The number says how many rooms the apartment has besides the kitchen area. The letters say what else is there.

• R (room): a studio. The kitchen is in the same room as the bed and the living space. A 1R is usually the smallest and cheapest type.
• K (kitchen): the kitchen is a separate small space, usually behind a door. A 1K has one room and a separate kitchen.
• DK (dining kitchen): a kitchen with space for a dining table. In a 1DK, the dining kitchen is a separate space from the single room.
• LDK (living, dining, kitchen): one large space that serves as living room, dining room and kitchen. A 2LDK has two bedrooms plus an LDK.
• S (service room, 納戸 nando): a room without a proper window, so it cannot be counted as a bedroom. It is often used for storage. A 2LDK+S has two bedrooms, an LDK and a service room.

So a "1LDK" is one bedroom plus a combined living, dining and kitchen space, and a "2K" is two rooms and a separate kitchen.

How big does a DK or an LDK have to be?

The Fair Competition Code for real estate advertising in Japan sets a guideline for the minimum size of a space that may be called a DK or an LDK. The minimum depends on the number of bedrooms.

These figures are the minimum for using the label, not the typical size. Because one jō counts as 1.62 m² in advertising, an LDK of 8 jō is at least 12.96 m². Check the number written next to LDK or DK in the listing, because some spaces only just reach the minimum.

Reading the room sizes

Next to the layout code you will usually see a list of rooms with their sizes, such as 洋室 6畳 or 和室 6畳. The word 洋室 (yōshitsu) means a Western-style room with a wood or carpet floor. The word 和室 (washitsu) means a Japanese-style room with tatami mats. Both are measured in jō, written 畳 or 帖, even when the floor has no tatami at all.

A jō in a listing is not a real mat. Under the advertising rules, one jō means at least 1.62 m², so a "6 jō" room is at least 9.72 m². Real tatami mats are a little bigger or smaller depending on the region. They range from about 1.45 m² for the danchima mats of apartment blocks to about 1.82 m² for the large kyoma mats of the Kansai area. The tatami calculator converts between jō, square meters and square feet for each mat type.

The floor area in square meters

The total area, such as 25.4㎡, is the floor area of the apartment itself. It is the number to use when you compare listings, because it does not depend on any type of mat. The balcony (バルコニー) is listed separately and is not included in the figure.

Here is a small example. Listing A is a 1K with 22.5㎡ and a 6 jō room. Listing B is a 1K with 20.1㎡ and a 6 jō room. Both say 6 jō, but A has 2.4 m² more floor area, which is about one and a half mats at the advertising standard. The difference may be in the kitchen, the entrance hall or the closets, or in the size of the mats.

Other words you will see

• 収納 (shūnō) or CL: a closet or storage space. WIC is a walk-in closet, and SIC is a walk-in space for shoes.
• 玄関 (genkan): the entrance hall, where you take off your shoes.
• UB: a unit bath, a bathroom made as one factory-built piece. バス・トイレ別 means the bath and the toilet are in separate rooms.
• 洗面所 (senmenjo): the washroom with a sink. A space for a washing machine is often written 洗濯機置場.
• バルコニー: the balcony. Its area is listed apart from the floor area.

What to check before you decide

Compare the floor area in square meters, not the number of jō. Look at the size written beside LDK or DK, because the minimum is low. And check whether the kitchen is a separate room (K) or part of the main room (R), since that changes how the apartment feels to live in. If a listing does not give the floor area, ask the agent for it.

Frequently asked questions

Is a Japanese "mansion" a mansion?

No. In Japan a manshon (マンション) is a mid-rise or high-rise apartment building, usually built of concrete. A smaller wooden or light-steel building is usually called an apāto (アパート). Both words can appear in rental listings.

What does 2LDK+S mean?

Two bedrooms, a combined living, dining and kitchen space, and a service room. The service room is a room without a proper window, often used for storage, that is not counted as a bedroom.

Why is one "6 jō" room bigger than another?

Two reasons. The mats may be different sizes, since Kansai mats are larger than Kanto mats. And in advertising, the number of jō is worked out from the floor area using at least 1.62 m² per jō, so it does not have to match the real mats in the room.

Sources

• Mitsubishi Estate real estate glossary (in Japanese): minimum sizes for DK and LDK under the Fair Competition Code for real estate advertising
• Metropolitan Real Estate Fair Trade Council glossary (in Japanese): at least 1.62 m² per jō in listings
• Mat dimensions are the commonly used sizes. They vary by region and by building.

Related pages

• Tatami room size calculatorJō to square meters and square feet, with the four regional mat sizes.
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• How ages are counted in JapanKazoedoshi, man-nenrei, unlucky years and the April 2 school-year cut-off.
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Last updated: 2026-10-04