Circle Calculator

Radius of a circle:



A free online circle calculator is used to calculate the radius, circumference, area and diameter of a circle along with the formula of the circle.

What is Circle

A circle is a closed plane curve that divides the plane into two regions, an interior and an exterior, such that every point on the curve is at a fixed distance from a fixed point. The fixed point is called the centre and the distance is called the radius.

Math formula

  • Area of circle = πr²
  • Circumference of circle = 2πr
  • diameter of circle = 2r

Solved Example

Example.:-Circle of Radius = 10 cm, find the area of a circle, the circumference of the circle and the diameter of the circle Area of the circle = πr² = 314.15927 cm²

Area of circle = πr² = 314.15927 cm²

Circumference of circle = 2πr = 62.83185 cm

Diameter of circle = 2r = 20 cm

How to use this circle calculator

Enter only the radius value in the input field and then click the calculate button, you see calculate the value in the answer box. but if you want to enter another value, clear the entered value and then enter the new radius value.

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