function byte_format($size) {
    $bytes = array( ' KB', ' MB', ' GB', ' TB' );
    foreach ($bytes as $val) {
        if (1024 <= $size) {
            $size = $size / 1024;
            continue;
        }
        break;
    }
    return round( $size, 1 ) . $val;
}

这是Chris Jester-Young的实现，我见过的最干净的，结合了php。net的和一个精度参数。

function formatBytes($size, $precision = 2)
{
    $base = log($size, 1024);
    $suffixes = array('', 'K', 'M', 'G', 'T');   

    return round(pow(1024, $base - floor($base)), $precision) .' '. $suffixes[floor($base)];
}

echo formatBytes(24962496);
// 23.81M

echo formatBytes(24962496, 0);
// 24M

echo formatBytes(24962496, 4);
// 23.8061M

下面是Drupal format_size函数的简化实现:

/**
 * Generates a string representation for the given byte count.
 *
 * @param $size
 *   A size in bytes.
 *
 * @return
 *   A string representation of the size.
 */
function format_size($size) {
  if ($size < 1024) {
    return $size . ' B';
  }
  else {
    $size = $size / 1024;
    $units = ['KB', 'MB', 'GB', 'TB'];
    foreach ($units as $unit) {
      if (round($size, 2) >= 1024) {
        $size = $size / 1024;
      }
      else {
        break;
      }
    }
    return round($size, 2) . ' ' . $unit;
  }
}

试试这个;)

function bytesToSize($bytes) {
                $sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
                if ($bytes == 0) return 'n/a';
                $i = intval(floor(log($bytes) / log(1024)));
                if ($i == 0) return $bytes . ' ' . $sizes[$i]; 
                return round(($bytes / pow(1024, $i)),1,PHP_ROUND_HALF_UP). ' ' . $sizes[$i];
            }
echo bytesToSize(10000050300);

这是Kohana的实现，你可以使用它:

public static function bytes($bytes, $force_unit = NULL, $format = NULL, $si = TRUE)
{
    // Format string
    $format = ($format === NULL) ? '%01.2f %s' : (string) $format;

    // IEC prefixes (binary)
    if ($si == FALSE OR strpos($force_unit, 'i') !== FALSE)
    {
        $units = array('B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB');
        $mod   = 1024;
    }
    // SI prefixes (decimal)
    else
    {
        $units = array('B', 'kB', 'MB', 'GB', 'TB', 'PB');
        $mod   = 1000;
    }

    // Determine unit to use
    if (($power = array_search((string) $force_unit, $units)) === FALSE)
    {
        $power = ($bytes > 0) ? floor(log($bytes, $mod)) : 0;
    }

    return sprintf($format, $bytes / pow($mod, $power), $units[$power]);
}

这是我的选择，简短明了:

/**
 * @param int $bytes Number of bytes (eg. 25907)
 * @param int $precision [optional] Number of digits after the decimal point (eg. 1)
 * @return string Value converted with unit (eg. 25.3KB)
 */
function formatBytes($bytes, $precision = 2) {
    $unit = ["B", "KB", "MB", "GB"];
    $exp = floor(log($bytes, 1024)) | 0;
    return round($bytes / (pow(1024, $exp)), $precision).$unit[$exp];
}

或者，更愚蠢和有效:

function formatBytes($bytes, $precision = 2) {
    if ($bytes > pow(1024,3)) return round($bytes / pow(1024,3), $precision)."GB";
    else if ($bytes > pow(1024,2)) return round($bytes / pow(1024,2), $precision)."MB";
    else if ($bytes > 1024) return round($bytes / 1024, $precision)."KB";
    else return ($bytes)."B";
}