Circle Calculator
Calculate all properties of a circle: area, circumference, diameter, and sectors.
Input method
Visualization
Circle Properties
Radius
5.0000
Diameter
10.0000
Circumference
0,0000
Area
0,0000
Formulas
CircumferenceC = 2πr
AreaA = πr²
Diameterd = 2r
π Constant
π ≈ 3.14159265359...
What is a Circle?
A circle is a flat figure where all points are equidistant from a central point called the center.
Parts of a Circle
Radius: distance from center to edge. Diameter: distance across through the center (2 × radius). Circumference: perimeter of the circle.
Applications
Circles are used in wheels, gears, pipes, coins, clocks, and in astronomy and physics calculations.