Geometry
Circle Circumference
Perimeter of a circle.
Formula
Formula
C = 2 π r
Variables
| Symbol | Definition | Type & range | Units | Role |
|---|---|---|---|---|
| r | radius | real number (ℝ) | — | input |
Try it yourself
Interactive calculator
Worked examples
Example 1
Givenradius r = 5
Result31.41592654
Example 2
Givenradius r = 1
Result6.283185307