Calculate Sectors of a Circle & Circle Arcs

A sector of a circle is the shape formed by slicing up a circular cake. The arc is the outer edge of the sector

Whether you want to calculate the Area (A), Arc (s), or one of the other properties of a sector including Radius (r) and the Angle formed, then provide two values of input. Select the input value you want, then enter their values.

The formulas to find the area of a sector in Degrees (D°) or Radians (R°) are shown below:

Area (Degrees) = πr2 x θ/360

Area (Radians) = ½r2θ

Radius (r)
Angle (D°)
Angle (R°)
Arc (s)
Area (A)

*Radius and Arc in units (e.g. metres), and area will be in unit squares (e.g. metre2). Angles will be in Radians or Degrees.