Math
Circle Circumference Calculator
Find the distance around a circle from its radius.
This result is the total distance around the edge of the circle, so a circle with this radius needs a border or tape of that length to go all the way around it.
Formula
Circumference = 2 × π × radius.
How it works
Enter the radius. The calculator multiplies it by 2 and by pi to give the length around the circle.
Worked example
For example, a radius of 5 gives 2 × π × 5 = 31.4159 units, so the circumference is 31.4159 units.
FAQs
What does the Circle Circumference do?
It takes the values you enter and works out the circle circumference for you, showing the result straight away.
What should I enter?
Enter ordinary numbers in the boxes above. If a value does not make sense for this calculation, the page will ask you to check it instead of showing a wrong answer.
Can I use the result for homework or everyday math?
Yes. It is a general-purpose math helper; for exam or professional work, still check the steps against your own working.
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