How many MP3s on a CD?

One of our clients asked a simple question - how many MP3s can I get on a CD?

He has a new car and the stereo will play digital music direct from a CD. So, how many can he put on each disc? Shouldn’t be too hard to answer.

OK, a standard CD with music, such as you used to buy in HMV, stores just over an hour, say 70 minutes. However in data terms that’s around 750 Mb.

MP3 music is in data file format so the roundabout answer is as much music as will take up 750 Mb. As a CD ripping service we rip at 256 kbps into AAC format, the equivalent in MP3 would be 320 kbps. In our format you’d get much more music in digital format, around 7 CDs worth. As MP3 files the answer would be around 5 CDs worth. Roughly.

You could get more if you dropped the quality setting, so the music files are more compressed. The quality is worse, but that may not be a problem if the in car sound system is less than top notch. You could go down to 128 kbps for music and the sound might be acceptable.

If you were recording spoken voice (such as audio books) you can drop as low as 64 kbps and the quality will be acceptable, there just isn’t so much data in a speech compared to a symphony.

So, how many MP3s can you get on a CD? This CD ripping service says 5,7 music CDs or 12 CDs worth of spoken voice.