PHP: Show File Size with B, kB, MB, GB or TB Unit

Today, I would like to introduce a function with which it is possible to display the size of a file in PHP.

The function takes care about using the correct fitting unit for the appropriate filesize such as kB or MB and optionally, you can specify the number of decimal places you would like to use.

function show_filesize($filename, $decimalplaces = 0) {

  $size = filesize($filename);
  $sizes = array('B', 'kB', 'MB', 'GB', 'TB');

  for ($i=0; $size > 1024 && $i < count($sizes) - 1; $i++) {
     $size /= 1024;
  }
  return round($size, $decimalplaces).' '.$sizes[$i];

}

You can use the function like that, for example:

echo show_filesize('text.txt');     // 12 kB
echo show_filesize('text.txt', 3);  // 12.345 kB
echo show_filesize('bigdata.txt');  // 89 TB

The first parameter we have to pass to the function is the file name/file path. The second parameter is optional and can be left. It can be used to adjust the number of decimal places.

By default, the decimal places are 0 here, but you can also adjust this in the function above ($decimalplaces = 0). You can also extend or rewrite the array $sizes if you would like to use other or more units.