C# program to find the area of a circle

C# program to find the area of a circle :

In this post, we will learn how to find the area of a circle in C sharp. We will take the radius as input from the user and calculate the area. With this program, you will learn how to take user inputs in C sharp and how to do mathematical calculations.

Formula to find the area of a circle:

Below formula is used to calculate the circle area:

π * r * r

Where, r is the radius and π is the mathematical constant Pi. We will take the value of radius from the user as input. For π, we can either define a variable and assign it upto a specific decimal place or we can use Math.PI constant that is available in C#.

C# program:

Below is the complete program to calculate circle area in C#:

using System;
public class Program
	public static void Main()
		int radius;
		double area;
		Console.WriteLine("Enter the value of radius: ");
		radius = int.Parse(Console.ReadLine());
		area = Math.PI * radius * radius;
		Console.WriteLine("Area of the circle is : "+ Math.Round(area,2));


  • radius is an int value to keep the radius of the circle.
  • area is a double to save the area of the circle.
  • We are using int.Parse to parse the user input number i.e. the radius.
  • The final area is stored in the double area
  • Finally, we are writing down the area of the triangle.

Sample output:

Enter the value of radius: 
Area of the circle is :314.16

You might also like: