Segment area calculator

Circular segment area = radius² × (angle in radians − sin(angle)) ÷ 2.

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Radius

Central angle (degrees)

Answer

…

Circular segment area = radius² × (angle in radians − sin(angle)) ÷ 2.

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Precision and calculation record

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Formula and assumptions

Angles above 180 degrees describe the major segment. This is the region between a chord and its arc, not the sector bounded by two radii.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Segment area calculator

Circular segment area = radius² × (angle in radians − sin(angle)) ÷ 2.

Angles above 180 degrees describe the major segment. This is the region between a chord and its arc, not the sector bounded by two radii.

Next: Arc length calculator

A worked example

With radius = 3, central angle (degrees) = 180, the segment area is 14.137166941154069.

Next: Circle calculator

Before you use the result

Angles above 180 degrees describe the major segment. This is the region between a chord and its arc, not the sector bounded by two radii.

Example results for radius

These examples use Central angle (degrees): 180. They are reference calculations, not recommended settings.

Radius	Segment area
1.5	3.53429173529
3	14.1371669412
6	56.5486677646

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