Circle Calculator

Calculate area, circumference, arc length, and sector area.

Circle Properties

Change any input — others update automatically

Radius (r)
Diameter (d = 2r)
Circumference (C = 2πr)
Area (A = πr²)
Arc & Sector (enter central angle)
Central Angle (θ)

Enter your values above and tap Calculate to see the result.

Your Results

Diagram