Circle Calculator
Enter any known circle measurement and get the remaining geometric properties.
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How to use
- 1Fill at least one positive field: radius, diameter, circumference or area.
About
Circle calculator based on π, with linear and square-unit results.
Circle calculator
Find the radius, diameter, circumference and area of a circle from any known measure.
d = 2r, C = 2πr and A = πr².
Enter radius, diameter, circumference or area; the other values are derived from the radius.
Circumference uses linear units and area uses square units.
Practical examples
- With radius 5, the diameter is 10, circumference is 31.416 and area is 78.540.
Limitations and notes
- Enter at least one positive measure and keep units consistent.
- Use valid values and keep all units consistent.
How to use
- 1Enter one known measure.
- 2Leave the other fields empty.
- 3Review every calculated measure.
Frequently asked questions
Which value should I enter?
Any of the four fields works. If several are filled, the first valid value is used.
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