显示数字不能正确转换

Question

我正在尝试转换一些数字。

$this->byte_convert($count)的当前输出为460.80 KB，但应显示为0.04 GB

如何显示这样的数字？

$quota = imap_get_quotaroot($mbox, "INBOX");

$message = $quota['MESSAGE'];

$percentage = ($count / $message['limit']) * 100;

echo $this->gb_convert($count) . " (" . round($percentage) . "%) of " . $this->byte_convert($message['limit']) . " used";

function byte_convert($size) {
    # size smaller then 1kb
    if ($size < 1024) return $size . ' Byte';
    # size smaller then 1mb
    if ($size < 1048576) return sprintf("%4.2f KB", $size/1024);
    # size smaller then 1gb
    if ($size < 1073741824) return sprintf("%4.2f MB", $size/1048576);
    # size smaller then 1tb
    if ($size < 1099511627776) return sprintf("%4.2f GB", $size/1073741824);
    # size larger then 1tb
    else return sprintf("%4.2f TB", $size/1073741824);
}

更新

我做了一个像

这样的功能

public function gb_convert($size) {
    return sprintf("%4.2f GB", $size/1073741824);
}

但输出为0.00

$count = 471858;

echo $this->gb_convert($count) . " (" . round($percentage) . "%) of " . $this->byte_convert($message['limit']) . " used";

回声的完整输出

0.00 GB (0%) of 2.00 GB used