MP3 Bitrate Sound Quality Chart

MP3 files can be created with a staggering variety of bitrates. What do the different bitrates mean, and which one should you use?

First, make sure you read about What Are Bitrates to understand what is being discussed here. In essence, a bit rate is the actual file space taken up by 1 second of music. MP3 files use a standard MP3 encoding process, but even so, a high quality MP3 encoder can 'squash' a MP3 file into much smaller space than a low quality MP3 encoder. So you could in essence have a resulting MP3 file that takes up less space, but has higher quality.

Still, here are general rules of thumb for working with MP3 files. Always get the best possible encoding software that you can to create files that are high quality sounding, but low file size on your hard drive. The chart compares the MP3 file with the size of the original CD file. The bitrates are given in kilobits of disk space used per second of music.

256 kb/s
CD quality sound
20% original file size

128 kb/s
FM quality sound
10% original file size
(ends up being around 1mb space per minute of song)

64 kb/s
AM quality sound
5% original file size
not recommended for listening enjoyment

Note that these settings are ONLY valid for MP3 encoding. WMA encoding is considered by many to be twice as good as MP3 encoding, meaning you could create a file that was "equivalent" space-wise to 128kb/s but which sounded just as good as CD quality.

Because file size can have nothing to do with quality when you move to higher quality encoding systems, the Ogg Vogis format doesn't even talk about bitrates per second. Instead, they talk about the quality of the file as compared to a CD recording.

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