Convert filesize from bytes to human readable format in PHP

human_filesize.php

/**
 * Converts filesize from bytes to human readable format.
 *
 * @param  number  $bytes
 * @param  number  $decimals
 * @return string
 */
function human_filesize($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];
}