# circumference

/ˌsɝˈkəmfɹəns/ (US) · /sɜːkˈʌmfɹəns/ (UK)

Source: https://englishreference.com/word/circumference
Updated: 2026-08-27

## Senses

### 1. distance around a circle

noun · CEFR B2

the total length of the outside edge of a circle or round shape.

For teachers: the linear distance around the edge of a closed curve or circular object.

- The scientist measured the circumference of the tree trunk to estimate its age.
- To calculate the circumference of the planet at the equator, early astronomers relied on precise observations of the sun's angle at different latitudes.

Usage: Usually functions as a countable noun; often used with the preposition 'of'.

### 2. the boundary line

noun · CEFR B2

the actual line that forms the edge of a circle.

For teachers: the set of points that constitute the boundary of a circle or similar geometric figure.

- He drew a series of small dots along the circumference of the circle.
- The architect designed the walkway to follow the circumference of the courtyard, creating a perfect loop for visitors.

## Examples

- The circumference of the earth is about 40,000 kilometers.
- To find the diameter, you can measure the circumference of the pipe and divide it by pi.
- The architect calculated the exact circumference of the dome to ensure the glass panels would fit perfectly around the structural frame.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.