Memory limit vs usage percent

memory_limit_usage_percent.php

<?php
$memory_limit = (int)trim(ini_get("memory_limit"),'M');
function echo_memory_usage() { 
    $mem_usage = memory_get_usage(true); 
    if ($mem_usage < 1024) 
        echo $mem_usage." bytes"; 
    elseif ($mem_usage < 1048576) {
        echo "memory usage: ".round($mem_usage/1024,2)." kilobytes"."<br>";
        echo "percent usage:".round((($mem_usage/1024) * 100 / ($GLOBALS['memory_limit'] * 1024)),2)."%"."<br>";
    }
    else {
        echo "memory usage: ".round($mem_usage/1048576,2)." megabytes"."<br>";
        echo "percent usage:".round((($mem_usage/1048576) * 100 / ($GLOBALS['memory_limit'])),2)."%"."<br>";
    } 
    echo "<br/>"; 
}
echo "memory limit: ".$GLOBALS['memory_limit']. " megabytes"."<br>";
for($i=1; $i<=10; $i++){
    //if wants to clear screen
    //ob_end_clean();
    echo "$i ...<br>";
    echo_memory_usage();
    sleep(1);
}
?>