PHP | gmp_sqrt() Function
Last Updated :
11 Jul, 2025
The gmp_sqrt() is a built-in function in PHP which is used to calculate the square root of a GMP number (
GNU Multiple Precision : For large numbers). This function returns only the integral part of the square root of the GMP number.
Syntax:
gmp_sqrt ( $num )
Parameters: This function accepts a GMP number
$num as a mandatory parameter as shown in the above syntax. This parameter can be a GMP object in PHP version 5.6 and later, or we are also allowed to pass a numeric string provided that it is possible to convert that string to a number.
Return Value: This function returns a GMP number which is the square root of a GMP number passed to it as parameter. This function only returns the integral part of the square root of the GMP number passed to it as argument.
Examples:
Input : "9"
Output : 3
Input : "24"
Output : 4
Below programs illustrate the gmp_sqrt() function in PHP :
Program 1: Program to calculate the square root of a GMP number when numeric strings as GMP numbers are passed as arguments.
php
<?php
// PHP program to calculate the square root
// of a GMP number passed as arguments
// strings as GMP numbers
$num1 = "9";
$num2 = "24";
// calculates the square root of a GMP number
$squareRoot = gmp_sqrt($num1);
echo $squareRoot."\n";
// calculates the square root of a GMP number
$squareRoot = gmp_sqrt($num2);
echo $squareRoot."\n";
?>
Output:
3
4
Program 2: Program to calculate the square root of a GMP number when GMP numbers are passed as arguments.
php
<?php
// PHP program to calculate the square root
// of a GMP number
// creating GMP numbers using gmp_init()
$num1 = gmp_init(9, 10);
$num2 = gmp_init(24, 10);
// calculates the square root of a GMP number
$squareRoot = gmp_sqrt($num1);
echo $squareRoot."\n";
// calculates the square root of a GMP number
$squareRoot = gmp_sqrt($num2);
echo $squareRoot."\n";
?>
Output:
3
4
Reference:
https://www.php.net/manual/en/function.gmp-sqrt.php