Calculate Script Execution Time

Calculate how long it takes to execute a script in PHP. Place a variable $time_start at the beginning of the script to get a start time. Place a print statement at the end of the script which displays the difference between the end and start of the script in microseconds.

<?php
$time_start = microtime(true); // place at start of script
/*
    - script goes here - 
*/
print "<hr><p>Execution time: " . (microtime(true) - $time_start) . " microseconds.</p>"; // end of script
?>

Example:

PHP

<?php
$time_start = microtime(true); // place at start of script
for ($i=0; $i<count($array); $i++) {
    calculate($stuff);
    calculatemore($stuff);
}
print "<hr><p>Execution time: " . (microtime(true) - $time_start) . " microseconds.</p>"; // end of script
?>

Produces the result: 
Execution time: 4.8610229492 microseconds.