Circumference Calculator
Result
Calculated result
31.4159265359
Based on the values entered.
↗ Math
Circumference Calculator — free online calculator.
Formula
C = 2 × π × r
- Circumference Calculator calculates its result from Radius. It uses the formula C = 2 × π × r. Change any input to recalculate the result instantly.
- The main inputs are Radius. Enter them in the units and format shown in the calculator.
- Keep comparable quantities in compatible units whenever the formula combines or compares them.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Circumference
Inputs
- Radius: 5
Using Radius = 5, the calculated result is 31.4159265359.
Sample result: Calculating…
Frequently asked questions
What does the Circumference calculate?
Circumference Calculator — free online calculator.
Which values should I enter?
Enter Radius using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: C = 2 × π × r.
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.