PHP function to get the folder size including subfolders

foldersize.php

<?php

function folderSize ($dir)
{
    $size = 0;

    foreach (glob(rtrim($dir, '/').'/*', GLOB_NOSORT) as $each) {
        $size += is_file($each) ? filesize($each) : folderSize($each);
    }

    return $size;
}

In GigaBytes:

return $size / 1e-9; //GigaBytes