Java Program to Find Number Square Root

Last Updated: 16 April, 2023

On this page, we are going to learn how to write a Java program to find a number's square root.

The square root of a number is a value that, when multiplied by itself, gives the original number. It is denoted by the symbol √ and can be calculated for any non-negative real number.

For example,

The square root of 9 is 3 because 3 multiplied by itself equals 9 (3 x 3 = 9).

Similarly,

The square root of 16 is 4 because 4 multiplied by itself equals 16 (4 x 4 = 16).

Example 1: Find Number Square Root in Java using Math.sqrt() method

  
  import java.util.Scanner;
  public class SqrRootOfNumber1 {
    public static void main(String[] args) {
      double square, squareRoot;
      Scanner scanner = new Scanner(System.in);
  
      System.out.print("Enter the Number: ");
      square = scanner.nextDouble();
      scanner.close();
      // Find square root using java.lang.Math.sqrt() method
      squareRoot = Math.sqrt(square);
      System.out.print("Square root of number " + square + " is " + squareRoot);
    }
  }

Output

Enter the Number: 64
Square root of number 64.0 is 8.0

Example 2: Find Number Square Root using Math.pow() method

  
  import java.util.Scanner;
  public class SqrRootOfNumber2 {
    public static void main(String[] args) {
      double square, squareRoot;
      Scanner scanner = new Scanner(System.in);
      
      System.out.print("Enter the Number: ");
      square = scanner.nextDouble();
      scanner.close();
      // Find square root using java.lang.Math.pow() method
      squareRoot = Math.pow(square, 0.5);
      
      System.out.print("Square root of number " + square + " is " + squareRoot);
    }
  }

Output

Enter the Number: 36
Square root of number 36.0 is 6.0

Example 3: Find Number Square Root using user defined method

  
  import java.util.Scanner;
  public class SqrRootOfNumber3 {
    public static void main(String[] args) {
      Scanner scanner = new Scanner(System.in);
      System.out.print("Enter a number: ");
      double num = scanner.nextDouble();
      scanner.close();
      System.out.println("Square root of number " + num + " is: " + findSquareRoot(num));
    }
    
    // User defined method for finding square root value
    public static double findSquareRoot(double num) {
      double temp;
      double sqrtroot = num / 2;
      do {
        temp = sqrtroot;
        sqrtroot = (temp + (num / temp)) / 2;
      } while ((temp - sqrtroot) != 0);
      return sqrtroot;
    }
  }

Output

Enter a number: 81
Square root of number 81.0 is: 9.0