Circle Calculator
Calculate circle area, circumference, and diameter from radius
About This Tool
The Circle Calculator determines properties of a circle such as area, circumference, diameter, and radius based on given input.
Enter one known value (area, circumference, diameter, or radius) to calculate the rest. The tool uses mathematical formulas for accurate results.
Suitable for geometry assignments, design projects, or any situation needing quick circle property calculations. No data is shared outside your browser.