Translation guide
The English word "size" refers to physical dimensions, magnitude, or a standardized measurement category. In Japanese, the most common equivalent is サイズ (saizu), a loanword used for clothing, shoes, and general dimensions. For abstract or physical magnitude, 大きさ (ōkisa) is used. When asking about size, どのくらい (dono kurai) or どれくらい (dore kurai) are natural. Be careful: directly translating "size" as 大きさ in contexts like clothing sizes can sound unnatural; use サイズ instead.
Expressing how big or small something is in terms of length, area, volume, etc.
General term for physical size or magnitude. Used for objects, animals, abstract concepts. Not typically used for clothing/shoe sizes.
この箱の大きさを測ってください。
Please measure the size of this box.
象の大きさに驚いた。
I was surprised by the size of the elephant.
Loanword from English. Used for standardized sizes (clothing, shoes, paper, etc.) and general dimensions. Very common in everyday speech.
Refers to precise measurements or dimensions, often used in technical contexts like construction, manufacturing, or tailoring.
Scale or scope, used for projects, events, businesses, etc. Emphasizes the extent or magnitude rather than physical measurements.
このプロジェクトの規模は大きい。
The scale of this project is large.
Referring to a specific size category like S, M, L, or shoe sizes.
The default word for clothing and shoe sizes. Use this in shops or when discussing fit.
How to ask 'what size?' or 'how big?' naturally.
Means 'about what size?' or 'how big?'. Use when asking for a description of physical dimensions.
その犬はどのくらいの大きさですか？
About what size is that dog?
Describing how spacious a room, house, or land is.
Refers to spaciousness or area. Commonly used for rooms, houses, and land.
Referring to the size of a group, company, or population.
Used for the scale of organizations, events, or projects. Often paired with 大きい/小さい.
Referring to the size of a digital file or data.
Commonly used for file sizes, screen dimensions, etc.
Metaphorical use: the size of a problem, achievement, etc.
Can be used metaphorically for the magnitude of abstract things.
While 大きさ means 'size' in the sense of physical magnitude, it is not used for standardized sizes like clothing or shoes. Use サイズ instead. Saying 服の大きさ sounds like you're asking about the physical dimensions of the garment rather than the size label.
この服のサイズはMですか？
Is this clothing size M?
大きさ is native Japanese and refers to the abstract or physical magnitude of something. サイズ is a loanword and is used for standardized measurements, especially in consumer contexts. For example, 箱の大きさ (the size of the box) vs. 靴のサイズ (shoe size).
The size of this T-shirt is M.
靴のサイズが合わない。
The shoe size doesn't fit.
設計図に寸法を記入する。
Enter the dimensions on the blueprint.
大きいサイズはありますか？
Do you have larger sizes?
サイズを測りましょうか？
Shall I measure your size?
Used for Japanese traditional clothing sizes or some specific items like rings. Not common for Western clothing.
着物のサイズは11号です。
The kimono size is 11.
Direct way to ask 'what size?' for clothing, shoes, etc.
あなたの靴のサイズは何ですか？
What is your shoe size?
Similar to どのくらい, slightly more casual. Used for asking about extent or magnitude.
その荷物はどれくらいの大きさですか？
How big is that luggage?
この部屋の広さは十分です。
The size of this room is sufficient.
土地の広さは100平方メートルです。
The size of the land is 100 square meters.
Formal term for area, used in real estate, geography, or mathematics.
このマンションの専有面積は70平方メートルです。
The exclusive area of this apartment is 70 square meters.
会社の規模は中くらいです。
The size of the company is medium.
Specifically refers to the number of people. Use when talking about group size.
パーティーの人数を教えてください。
Please tell me the size of the party (number of people).
このファイルのサイズが大きすぎます。
The size of this file is too large.
Refers to capacity or storage size, often used for memory, hard drives, etc.
スマホの容量がいっぱいです。
The phone's storage size is full.
He doesn't understand the size of the problem.
Emphasizes seriousness or gravity. More formal.
事件の重大さに気づいた。
I realized the size (seriousness) of the incident.