Geometry & Shape Calculators >

Circle Calculator

Calculate area, circumference, and radius.

How to use Circle Calculator

  1. Input: Enter any one known variable.
  2. Calculate: Instantly see all 4 circle properties.

About Circle Calculator

The Circle Calculator computes properties of a circle from just one input. Enter the Radius, Diameter, Circumference, or Area, and we calculate the rest.

Uses high-precision Pi (π) for accurate engineering results.