Human Readable File Size with PHP

gistfile1.php

<?php
# http://jeffreysambells.com/2012/10/25/human-readable-filesize-php
function human_filesize($bytes, $decimals = 2) {
    $size = array('B','kB','MB','GB','TB','PB','EB','ZB','YB');
    $factor = floor((strlen($bytes) - 1) / 3);
    return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . @$size[$factor];
}

echo human_filesize(filesize('example.zip'));

Another version, eliminates needless count()

just FYI: count is "free" operation in php, cause array always have its size in internal structure.