Bitrate, is a term used to describe the amount of bits per second used to store the the audio
information being encoded or decoded from a digital audio file, in our case, an MP3 song.
Bitrates are generally measured in kilobits per second (kbps), and you will usually see bitrates
of 128kbps, 160 kbps, 192 kbps, 256 kbps, 320 kbps, etc.
It is usually argued that 128 kbps is near CD quality, but most people will encode their songs at
higher rates, usually 192 kbps or higher. There also appears to be a point of diminishing
returns, where going higher, does not necessarily result in better sounding MP3 music files.
Most disc jockeys for example, will encode their songs to a bitrate of 192 kbps, as this is
usually the minimum that they find acceptable to their audience, and yet going higher, say to
256 or 320, does not make a noticeable difference in quality, yet the file sizes increase quite a
For years, many people sharing their files over the internet using Napster, Kazaa, Morpheus,
etc., used 128 kbps. But, more and more these days, you are finding people ripping and
encoding to the higher 160 or 192 kbps bitrate.
Some examples of file sizes produced by differing bitrates are shown below, this is for a song
with the length of 3 minutes 48 seconds, called Have A Nice Day, by Bon Jovi:
WAV file size : 39,386 KB
MP3 128kbps : 3,574 KB
MP3 192kbps : 5,360 KB
MP3 320kbps : 8,933 KB
As you can see, there is a substantial increase in file size as we progress to higher bitrates for
the encoded file. Many people can tell the difference between a file encoded at 128 vs. 192, but
few can tell the difference between those encoded at 192 vs. 320. Hence, the point about