Translation guide
The area of a room or building, often measured in square meters or tatami mats. In Japanese, the most common way to express this is 床面積 (ゆかめんせき) for technical contexts, but in everyday conversation, people often refer to the size of a room using 広さ (ひろさ) or the number of tatami mats (畳, じょう).
To refer to the total floor area in architectural, real estate, or official contexts.
The standard term for floor space or floor area, used in building plans, property listings, and legal documents.
この家の床面積は100平方メートルです。
The floor space of this house is 100 square meters.
Total floor area, often used in building regulations to refer to the sum of all floors.
延べ床面積が200平方メートルを超えると規制が厳しくなります。
If the total floor space exceeds 200 square meters, regulations become stricter.
To talk about how spacious a room feels or its dimensions in casual settings.
Literally 'spaciousness', this is the most natural way to refer to the size or floor space of a room in daily speech.
この部屋の広さはどれくらいですか？
How big is this room? (lit. What is the floor space of this room?)
リビングの広さが気に入りました。
I liked the size of the living room.
Rooms in Japan are often measured by the number of tatami mats. One tatami is roughly 1.65 m². This is the most common way to express room size in everyday life.
この部屋は6畳です。
This room is 6 tatami mats (about 10 m²).
8畳の和室を探しています。
I'm looking for an 8-tatami Japanese-style room.
Literally 'room area', a slightly more formal way to talk about floor space, but still used in conversation.
部屋の面積を測ってください。
Please measure the floor space of the room.
To emphasize the practical, usable area of a room, not just the total dimensions.
Effective floor area, used in architecture or interior design to describe the space that can actually be used after accounting for pillars, stairs, etc.
有効床面積を最大化する設計です。
It's a design that maximizes usable floor space.
広さ (ひろさ) is a general word for 'size' or 'spaciousness' and is used in everyday conversation. 床面積 (ゆかめんせき) is a technical term for 'floor area' and is used in real estate, architecture, and official documents. When in doubt, use 広さ for casual talk about room size.
このアパートの床面積は狭いですが、広さは感じます。
The floor area of this apartment is small, but it feels spacious.
In Japan, room size is often given in 畳 (じょう), the number of tatami mats. This is especially common for Japanese-style rooms (和室, わしつ) but also used for Western-style rooms. Note that tatami sizes vary slightly by region, but a standard is about 1.65 m².
新しい機器のためにもっと床面積が必要です。
We need more floor space for the new equipment.
Formal context, e.g., in a business setting.