Circle Calculator
Calculate radius, diameter, circumference and area.
- Radius
- 5
- Diameter
- 10
- Circumference
- 31.4159
- Area
- 78.5398
Enter any one property of a circle to compute the radius, diameter, circumference and area.
How to use
- Choose which property you know.
- Enter its value.
- Read the other three properties.
Frequently asked questions
- What formulas are used?
- Circumference = 2πr and area = πr², derived from the radius.
- What units are used?
- Whatever unit you enter; area is in those units squared.