Measuring script execution time in PHP

Script execution time in PHP is the time required to execute the PHP script. To calculate script execution time use clock time rather than the CPU execution time. Knowing clock time before script execution and after script execution will help to know the script execution time.

Example: Sample script

<?php
for($i = 1; $i <=1000; $i++)
{
    echo "Hello Geeks!";
}
?>

Clock time can get using microtime() function. First use it before starts the script and then at the end of the script. Then using formula (End_time – Start_time). The microtime() function returns time in seconds. Execution time is not fixed, it depends upon the processor.

Example:

<?php

// Starting clock time in seconds
$start_time = microtime(true);
$a=1;

// Start loop
for($i = 1; $i <=1000; $i++)
{
    $a++;
}

// End clock time in seconds
$end_time = microtime(true);

// Calculate script execution time
$execution_time = ($end_time - $start_time);

echo " Execution time of script = ".$execution_time." sec";
?>

Output:

Execution time of script = 1.6927719116211E-5 sec