capacity

capacity — noun

1. the greatest amount that a container, space, machine, or system can hold or prod

1.nounB2
Definition

the greatest amount that a container, space, machine, or system can hold or produce — for example, the number of litres a fuel tank can hold, or the number of people a theatre can seat.

Example

The fuel tank of Kofi's car has a capacity of fifty litres.

capacity of + volume measure

The concert hall was filled to capacity with cheering fans.

filled to capacity

Common collocations
  • full capacity
  • storage capacity
  • seating capacity
  • production capacity
  • capacity of
  • at capacity
  • beyond capacity
Synonyms
  • volume

    focuses on three-dimensional space rather than an abstract maximum

  • size

    more general — can refer to dimensions without implying a maximum limit

  • output

    used for the amount produced by a factory or machine, not for containers

Antonyms
  • shortage

    a situation where there is less than the capacity

Grammar Patterns

capacity + for + noun/gerund

capacity + of + number

in/at + full capacity

Usage Note

When talking about the total amount a space can hold, capacity is usually uncountable (The airport reached its capacity). It is countable when you give a specific measurement (a capacity of two hundred seats).

Common Mistakes

The bottle has a big capacity
The bottle has a capacity of one litre.
Use a specific number rather than a vague adjective with capacity.
The meeting room is at the capacity
The meeting room is at full capacity.
Use full before capacity when the space is completely filled.

2. a person's natural or learned ability to do, understand, or produce something —

2.nounB2
Definition

a person's natural or learned ability to do, understand, or produce something — for example, a child's capacity to learn new languages quickly, or an athlete's capacity for hard training.

Example

Young children have an amazing capacity to absorb new information.

capacity + to-infinitive — natural ability

Leila showed a remarkable capacity for patience when dealing with difficult customers.

capacity for + noun/gerund

Common collocations
  • capacity for
  • capacity to
  • great capacity
  • limited capacity
  • mental capacity
  • physical capacity
  • intellectual capacity
Synonyms
  • ability

    more general and more common; capacity often implies a potential that may not yet be fully used

  • capability

    similar to capacity but slightly more formal; often used for machines or systems

  • aptitude

    focuses on a natural talent for a specific type of activity, e.g. musical aptitude

Antonyms
  • inability

    the lack of ability or means to do something

  • incapacity

    formal term for being unable to function normally

Grammar Patterns

capacity + to-infinitive

capacity + for + noun/gerund

Usage Note

This sense is always singular. The to-infinitive pattern (capacity to do something) is more common than the for + gerund pattern. Distinguish from sense 1 (AMOUNT CONTAINED): sense 2 is about a person's mental or physical ability, not about how much something holds.

Common Mistakes

He has the capacity of solving the problem
He has the capacity to solve the problem.
Use the to-infinitive, not of + gerund.
Her capacities are improving
Her capacity is improving.
This sense is uncountable/singular; do not use the plural.

3. the official position, job, or role that someone holds, especially when stating

3.nounC1
Definition

the official position, job, or role that someone holds, especially when stating how they are acting in a particular situation — for example, speaking in your capacity as the company lawyer, or working in a voluntary capacity.

Example

Dr. Okafor attended the meeting in her capacity as head of research.

in her capacity as + role

Theo signed the contract in his capacity as managing director.

in his capacity as + formal job title

Common collocations
  • in one's capacity as
  • in a ... capacity
  • official capacity
  • personal capacity
  • professional capacity
  • private capacity
  • advisory capacity
Synonyms
  • role

    less formal than capacity; used in everyday speech

  • position

    emphasises the job title or rank rather than the function being performed

  • function

    focuses on what a person actually does rather than their official title

Grammar Patterns

in + possessive + capacity + as + noun

in a/your capacity as + noun

acting in a + adjective + capacity

Usage Note

Frequently appears in the fixed expression in one's capacity as (someone/something). The adjective before capacity often marks the kind of role: official, professional, personal, private, judicial, advisory, etc. This sense is formal and most common in workplace, legal, or official contexts.

Common Mistakes

He joined the team as a capacity of manager
He joined the team in his capacity as manager.
Use in one's capacity as, not as a capacity of.
She works in voluntary capacity
She works in a voluntary capacity.
Always include the article a or possessive pronoun.

Word family

  • capacious
    adjectiveC2
  • incapacity
    nounC1
  • incapacitate
    verbC2
  • capability
    nounB2
  • capable
    adjectiveB1
  • incapable
    adjectiveB2

Synonym discussion

Sense: noun/2

All four words refer to a person's power to do something, but they differ in nuance. Ability is the broadest and most neutral term — it simply means being able to do something, whether naturally or through learning (she has the ability to explain complex ideas clearly). Capability emphasises a potential that may not yet be developed or demonstrated (the team has the capability to win the championship with more training). Aptitude points to a natural talent for a specific area, such as art or mathematics (he showed an early aptitude for languages). Competence focuses on having enough skill to do something to an acceptable standard, without implying excellence (she proved her competence in managing the project budget). Capacity, the headword here, often suggests a potential maximum — not just ability but the upper limit of what someone can do. For example: He has the capacity to become a world-class violinist implies a high ceiling of potential, whereas He has the ability to play the violin simply states he can play it.

ability ↗capability ↗aptitudecompetence ↗

Common collocations

Nouns

Adverbs

Phrases

  • to capacity
  • at full capacity
  • in one's capacity as
  • beyond one's capacity
  • within one's capacity

Prepositions

Etymology

LatinFrenchEnglish

Capacity comes from the Latin word capacitatem, meaning 'ability to hold or contain', which is based on capax ('able to hold much'). The root cap- is also the source of 'capture', 'captive', and 'accept'. The word entered English through French in the 1400s, originally referring to physical space and later extending to mental ability and official roles.