Circle Circumference & Area Calculator
Calculate a circle's radius, diameter, circumference, and area from any one measurement.
How to Use
- Choose the measurement you know, enter its value and unit, then choose decimal precision.
Assumptions and Limits
The tool models a mathematically perfect circle; area is expressed in squared units.
Method
diameter = 2r; circumference = 2πr; area = πr².
Examples
Example
A radius of 10 cm produces a circumference of about 62.83 cm.
Result: The calculator updates its results immediately from these inputs.
Frequently Asked Questions
What does the Circle Circumference & Area Calculator estimate?
Exact π forms are included where useful; rounded results use your selected precision.