Circle Calculator

Enter any one circle measurement to calculate radius, diameter, circumference, and area together.

Known measurement

Value

Radius = 5Solve the entire circle from one measurement.

10Diameter

31.415927Circumference

78.539816Area

How to use this Circle Calculator

Solve a circle from radius, diameter, circumference, or area. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.