Find the area of a circular sector, the pie slice shape cut from a circle by two radii. The area equals the central angle as a fraction of a full turn multiplied by the whole circle area, so in degrees it is the angle over 360 times pi r squared. For a radius of 10 and an angle of 90 degrees, the sector area is about 78.54 square units, exactly one quarter of the circle. This calculator also reports the arc length along the curved edge, which is the same fraction of the full circumference. Sectors appear in pie charts, fan blades, protractors, pizza slices and clock faces. Enter the radius in any unit and the angle in degrees, and the area returns in your unit squared while the arc length keeps your linear unit. Everything runs locally in your browser at full precision, and the copy button grabs the area instantly.
A sector is a pie-slice region bounded by two radii and the arc between them.
It scales the full circle area of pi times radius squared by the central angle over 360 degrees.
Enter the central angle in degrees, from 0 up to 360 for a full circle.
Find the area of a circular sector, the pie slice shape cut from a circle by two radii. The area equals the central angle as a fraction of a full turn multiplied by the whole circle area, so in degrees it is the angle over 360 times pi r squared.
Yes. Sector Area Calculator is completely free, with no sign-up and no usage limits.
Yes. Sector Area Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Sector Area Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.