function formatBytes($bytes, $precision = 2)
{
$sizes = array('B', 'KB', 'M', 'GB', 'TB');
$base = log($bytes, 1024);
return round(pow(1024, $base - floor($base)), $precision) . ' ' . $sizes[floor($base)];
}
echo formatBytes(disk_free_space("c:")) . "<br />";
echo formatBytes(disk_free_space("c:"), 3) . "<br />";
/*
run:
13.14 GB
13.144 GB
*/