Japanese Room Size Units (Tatami and Square Meters)

Learn how to read housing listings that use terms like 1K, 6 tatami, and 30 square meters.

Japanese property listings use their own style of notation, and it can be confusing at first.

Layout labels

• 1R (one room): A studio with the kitchen area in the same space as the main room.
• 1K: A single room plus a separate kitchen area smaller than about 4.5 tatami mats.
• 1DK: A dining-kitchen area of about 4.5 to 8 tatami mats plus a separate room.
• 1LDK: A living-dining-kitchen area of 8 tatami mats or more plus a separate room.
• 2K / 2DK / 2LDK: Two separate rooms.

What tatami means

Tatami is a traditional Japanese floor material, but it is also used as a unit for room size.

• 1 tatami mat is about 1.62 square meters, though the exact size varies by region.
• 6 tatami mats are about 9.72 square meters.
• 8 tatami mats are about 12.96 square meters.

If you are more familiar with square feet:

• 1 square meter is about 10.76 square feet
• 30 square meters is about 323 square feet and feels quite small
• 50 square meters is about 538 square feet and is more comfortable for one person

Be careful with “exclusive floor area”

The number shown in square meters is usually the apartment’s official floor area. Depending on the listing, wall thickness may be included, so the space you can actually use can feel slightly smaller.

Japanese apartments are generally small

For a one-person apartment in Tokyo, 20 to 35 square meters is very common. This is often smaller than a typical US studio apartment. Before buying furniture, it is a good idea to measure the actual width and depth of the room.