Circle Sector Area Calculator
Find the area and arc length of a circle sector.
A slice of the circle
A sector is a pie slice of a circle, set by a radius and the angle it sweeps. Its area and arc length are simply that angle’s share of the whole circle. This calculator finds both.
A sector of radius 6 spanning 90 degrees has an area of about 28.3 and an arc length near 9.42 — a quarter of the full circle. Enter your own radius and angle for exact values.
Precise and private
The calculation runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
What is a sector?
A pie-slice of a circle bounded by two radii and the arc between them.
What is the formula?
The area is the angle’s fraction of the full circle times the circle’s area; the arc length is that fraction of the circumference.
What angle units?
Degrees, from 0 to 360.
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