<?
  $sql = mysql_connect("host", "user", "passwort");

  $query = "SHOW TABLE STATUS FROM datenbank";
  $result = mysql_query($query);
  $sum = 0;
  while ($row = mysql_fetch_array($result))
  {
     $size = ($row["Data_length"] + $row["Index_length"]) / 1024;
     $name = $row["Name"];
     echo $name . "  " . $size  . " KB
";
     $sum += $size;
  }

  echo "Größe der DB = $sum KB";

  mysql_close($sql);
?>