Depends on the quality, lenght, but I would say 2....All I do is keep some small clips and some vodcasts on mine as I like a lot of music. But I'll take some time and try a few ways of converting and come up with as anwser for sure as I would like to know to. I just recently traded in my 4gig for a 8gig and have some more room to play with. I have one 6 and a half min. clip and its 104 megs....so times 10 for an hour is around a gig. Now I know there's varibles but thats a good start to go on. I'll post later with my results.