Number.humanBytes()

number_humanBytes.js

// Convert bytes to string '123.6 KiB', MiB, etc.
// var bytes = 8765432
// var human = bytes.humanBytes( 2 )
// 8.36 MiB
Number.prototype.humanBytes = function( decimals ) {
  var units = ['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'];
  var unit = 'B';
  var bytes = this.valueOf();
  var dec = decimals ? Math.pow( 10, decimals ) : 1;
  var i = 0;

  while( bytes >= 1024 ) {
    if( units[i] == undefined ) {
      break;
    }
    bytes = bytes / 1024;
    unit = units[i];
    i++;
  }

  bytes = Math.round( bytes * dec ) / dec;
  return bytes +' '+ unit;
}