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Circle Calculator
circle calculator
Circle Calculator
Calculate radius, diameter, circumference, and area of a circle
Radius
5
Diameter
10
Circumference
31.415927
Area
78.539816²
Using \u03C0 = 3.1415926536...
How to use
- 1
Choose the value you know (radius, diameter, etc.).
- 2
Enter the value.
- 3
All other circle values are calculated.
FAQ
Is this tool free?
Yes — no sign-up, no installation, completely free to use right away.
What is this tool?
This tool handles more advanced math so you don't have to do it by hand. Crunch matrices, statistics, or geometry and get accurate results in a moment. Everything is calculated in your browser.