Geometry
Circle circumference calculator
Compute the circumference of a circle (C = 2·π·r), with unit conversion.
Enter Radius to calculate Circumference. Results update instantly as you type. Use the unit dropdowns to switch units. Try an example preset to sanity-check the tool.
About this tool
- Inputs: Radius
- Outputs: Circumference
- Units: Use dropdowns to convert where available.
Formulas
Circumference
Circumference = 2 × π × RadiusRelated tools
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