In response to http://stackoverflow.com/questions/2602612/php-remote-file-size-without-downloading-file -> http://stackoverflow.com/a/25900273/624466

curlGetRemoteFilesize.php

<?php
/**
 *  Get the file size of any remote resource (using curl),
 *  either in bytes or - default - as human-readable formatted string.
 *
 *  @author  Stephan Schmitz <eyecatchup@gmail.com>
 *  @license MIT <http://eyecatchup.mit-license.org/>
 *  @url     <https://gist.github.com/eyecatchup/f26300ffd7e50a92bc4d>
 *
 *  @param   string   $url          Takes the remote object's URL.
 *  @param   boolean  $formatSize   Whether to return size in bytes or formatted.
 *  @param   boolean  $useHead      Whether to use HEAD requests. If false, uses GET.
 *  @return  string                 Returns human-readable formatted size
 *                                  or size in bytes (default: formatted).
 *
 *  <code>
 *  //example
 *  echo getRemoteFilesize('https://github.com/eyecatchup/SEOstats/archive/master.zip');
 *  </code>
 */
function getRemoteFilesize($url, $formatSize = true, $useHead = true)
{
    $ch = curl_init($url);

    curl_setopt_array($ch, array(
        CURLOPT_RETURNTRANSFER  => 1,
        CURLOPT_FOLLOWLOCATION  => 1,
        CURLOPT_SSL_VERIFYPEER  => 0,
        CURLOPT_NOBODY          => 1,
    ));

    if (false !== $useHead) {
        curl_setopt($ch, CURLOPT_NOBODY, 1);
    }

    curl_exec($ch);
    // content-length of download (in bytes), read from Content-Length: field
    $clen = curl_getinfo($ch, CURLINFO_CONTENT_LENGTH_DOWNLOAD);
    curl_close($ch);

    // cannot retrieve file size, return "-1"
    if (!$clen) {
        return -1;
    }

    if (!$formatSize) {
        return $clen; // return size in bytes
    }

    $size = $clen;
    switch ($clen) {
        case $clen < 1024:
            $size = $clen .' B'; break;
        case $clen < 1048576:
            $size = round($clen / 1024, 2) .' KiB'; break;
        case $clen < 1073741824:
            $size = round($clen / 1048576, 2) . ' MiB'; break;
        case $clen < 1099511627776:
            $size = round($clen / 1073741824, 2) . ' GiB'; break;
    }

    return $size; // return formatted size
}

$url = 'https://dl.google.com/dl/android/aosp/hammerhead-mra58k-factory-52364034.tgz';
echo getRemoteFilesize($url); // echoes "565.66 MiB"

GetRemoteFilesize.php

<?php
/**
 *  Get the file size of any remote resource (using get_headers()),
 *  either in bytes or - default - as human-readable formatted string.
 *
 *  @author  Stephan Schmitz <eyecatchup@gmail.com>
 *  @license MIT <http://eyecatchup.mit-license.org/>
 *  @url     <https://gist.github.com/eyecatchup/f26300ffd7e50a92bc4d>
 *
 *  @param   string   $url          Takes the remote object's URL.
 *  @param   boolean  $formatSize   Whether to return size in bytes or formatted.
 *  @param   boolean  $useHead      Whether to use HEAD requests. If false, uses GET.
 *  @return  string                 Returns human-readable formatted size
 *                                  or size in bytes (default: formatted).
 *
 *  <code>
 *  //example
 *  echo getRemoteFilesize('https://github.com/eyecatchup/SEOstats/archive/master.zip');
 *  </code>
 */
function getRemoteFilesize($url, $formatSize = true, $useHead = true)
{
    if (false !== $useHead) {
        stream_context_set_default(array('http' => array('method' => 'HEAD')));
    }
    $head = array_change_key_case(get_headers($url, 1));
    // content-length of download (in bytes), read from Content-Length: field
    $clen = isset($head['content-length']) ? $head['content-length'] : 0;
    // cannot retrieve file size, return "-1"
    if (!$clen) {
        return -1;
    }
    if (!$formatSize) {
        return $clen; // return size in bytes
    }
    $size = $clen;
    switch ($clen) {
        case $clen < 1024:
            $size = $clen .' B'; break;
        case $clen < 1048576:
            $size = round($clen / 1024, 2) .' KiB'; break;
        case $clen < 1073741824:
            $size = round($clen / 1048576, 2) . ' MiB'; break;
        case $clen < 1099511627776:
            $size = round($clen / 1073741824, 2) . ' GiB'; break;
    }
    return $size; // return formatted size
}
$url = 'https://dl.google.com/dl/android/aosp/hammerhead-mra58k-factory-52364034.tgz';
echo getRemoteFilesize($url); // echoes "565.66 MiB"

I was looking for him ...
thank you very much.