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Switch tool with the current settings for radius, and calculate circle area, circle diameter, sphere volume or sphere surface area instead
- Calculate circumference of circle from radius
- Circle area to radius calculator
- Circle diameter to radius calculator
- Length and distance converter
- Sphere volume to radius calculator
- Sphere surface area to radius calculator
This tool will calculate the radius of a circle from the circumference, and will convert different measurement units for circumference and radius.
The formula used to calculate the circle radius is:
r = C / (2 · π)
- r = Circle radius
- C = Circle circumference
- π = Pi = 3.14159…
Circumference of Circle
Enter the circumference which is the total length of the edge around the circle, if it was straightened out.
Radius of Circle
This is the radius of a circle that corresponds to the specified circumference. The radius is the distance between the centre and any point on the outer edge of a circle.