<?php
function fsize($path) { 
      $fp = fopen($path,"r"); 
      $inf = stream_get_meta_data($fp); 
      fclose($fp); 
      foreach($inf["wrapper_data"] as $v) { 
        if (stristr($v, "content-length")) { 
          $v = explode(":", $v); 
          return trim($v[1]); 
        } 
      } 
      return 0;
    } 
?>

<?php
$file = "https://downloads.wordpress.org/plugin/wordpress-seo.22.6.zip"; 
$inbytes = fsize($filesize);
echo $inbytes;
?>