Circle Circumference Calculator

Enter the radius to get the circle's circumference using the formula 2πr.

For educational use.

Examples

  • radius 5 ⇒ 31.42 units
  • radius 10 ⇒ 62.83 units

FAQ

Can I use diameter instead?

Divide diameter by 2 to get radius first.

What value of π is used?

The calculator uses π ≈ 3.14159.

Additional Information

  • Result unit: units