Area and Perimeter > Circle

# Area and Perimeter: Circle

This online calculator is a free online tool to help you in calculate area and perimeter of Circle.

## Calculator

### Enter 1 value

 Radius (r) = Diameter (d) =
Round to decimal places.
 Area A = Perimeter P =

## Formula

• P – perimeter
• A – area
• d – diameter
• O – centre

You may need: Area and Perimeter of Square

## Circle

Circle is a round, two-dimensional shape, and all points on the edge have the same distance from the center of the circle. Circle is a closed shape. The distance from the center of the circle to any edge point of it is called radius (r). The longest distance from one end point of a circle to the other is called diameter, simply it is two times from the radius. To count/calculate the circle, do not forget to use the mathematical constant π (phi). The number of π is 3,14 or 22/7.

## The standard formula to count the Area of Circle

A=π.r2
A= Area
π=3.14 or 22/7
d= diameter (2 times of r or 2.r)

P=π.d or 2.π.r
P= Perimeter
π=3.14 or 22/7