Circle Calculator
Calculate circle diameter, circumference, and area.
Diameter
10
Circumference
31.4159
Area
78.5398
Formula
area = pi*r^2, circumference = 2*pi*r
Calculate circle diameter, circumference, and area.
How to Use
Calculate circle diameter, circumference, and area. Enter the Radius values and review the Diameter, Circumference, and Area outputs after you calculate.
- Open the calculator : Start with Circle Calculator.
- Enter values : Fill in the required inputs and any optional settings.
- Review the result : Read the output and use the about page for more detail if needed.
Common Questions
What formula does the Circle Calculator use?
Area = ?r?. Circumference = 2?r.
Which measurement matters most in the circle calculator?
The radius controls every result, and the diameter is just twice the radius.