Translation guide
The English word "capacity" has several distinct meanings. This guide helps you choose the right Japanese expression depending on whether you mean physical holding ability, mental ability, role, or maximum output.
The maximum amount something can hold or contain.
Most common word for the capacity of a container, hard drive, battery, etc. Focuses on volume or data size.
このバッテリーの容量は5000mAhです。
This battery has a capacity of 5000mAh.
ハードディスクの容量がいっぱいになった。
The hard disk capacity is full.
Used for the capacity of a venue, stadium, or facility to hold people. More formal.
このスタジアムの収容能力は5万人です。
This stadium has a capacity of 50,000 people.
The fixed number of people allowed (e.g., in an elevator, car, or room). Often seen on signs.
エレベーターの定員は10名です。
The elevator capacity is 10 persons.
The ability to understand, learn, or do something.
General word for ability or capability. Works for intellectual or physical capacity.
彼にはその仕事をこなす能力がある。
He has the capacity to handle that job.
子供の学習能力はすばらしい。
Children's learning capacity is amazing.
Loanword from English. Often used in business contexts for mental bandwidth or workload limit.
Literally 'allowable amount', used for mental or emotional tolerance capacity.
The official position or function someone holds.
Pattern meaning 'in one's capacity as...'. Attach to a role noun.
私は社長としてこの会議に出席した。
I attended this meeting in my capacity as president.
彼は弁護士としてではなく、友人として来た。
He came not in his capacity as a lawyer, but as a friend.
Can mean 'capacity' in the sense of official status or credentials.
The maximum amount that can be produced or processed.
Production capacity, often used for factories or industrial output.
この工場の生産能力は年間10万台です。
This factory's production capacity is 100,000 units per year.
Processing capacity, for computers, sewage plants, etc.
容量 (capacity of a container) cannot be used for a person's mental ability. Use 能力 instead.
彼は容量が大きい。
He has a large capacity. (unnatural)
容量 is for volume/data; 収容能力 is for holding people in a large venue; 定員 is the fixed number of people allowed in a vehicle or room.
今は新しいプロジェクトを始めるキャパシティがない。
I don't have the capacity to start a new project right now.
ストレスの許容量を超えた。
I exceeded my capacity for stress.
He gave his opinion in his capacity as an expert.
サーバーの処理能力を増強する必要がある。
We need to increase the server's processing capacity.