Typical MP3 File Size
By Mara Shannon
The typical file size of an MP3 depends on a number of different factors, including the length of the audio and the bitrate, which determines the audio quality of the file.
The typical encoding standard for MP3 files is 128 kilobits per second (kbps, kb/s or kbit/s). This works out to about 1 megabyte (MB) per minute of sound.
You can encode MP3s at lower bitrates, such as 64 kbps. This cuts the file size in half, to 500 kilobytes (KB) per minute of sound, but significantly lowers the audio quality.
The average MP3 is much smaller than the average audio file on a CD, which takes up about 10 MB per minute. However, it is slightly larger than an AAC file of the same sound quality.