Circle Calculator
Calculate circle with Calculator 360 using the available inputs.
Try an example
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How to use this calculator
A circle with radius r has circumference 2πr and area πr². Its diameter is 2r.
Choose the known measurement and one length unit. Area is shown in the square of that unit.
Frequently asked questions
Are perimeter and circumference the same?
Yes. Both refer to the length around the circle.
What unit is used for area?
The square of the chosen length unit, such as cm².