â Circle Calculator
Get the diameter, circumference and area of a circle from its radius.
How to use the Circle Calculator
- Enter Radius.
- The result updates instantly as you type.
- Copy or note down your result.
How it works
Circumference = 2 x pi x r; area = pi x r2.
Example
Using the default values (Radius: 7):
Diameter14
Circumference43.9823
Area153.938
FAQ
Is the Circle Calculator free to use?
Yes. It is free, needs no signup and has no usage limits.
Is my data safe?
Yes. Everything is calculated in your browser, so what you type or upload is never sent to a server.
Can I use it on my phone?
Yes. KsWebProduction is built mobile-first and works in any modern browser.