If you data burn and your CD size is big enough you'll fit it, most blank CD's are 700-800 megs. It all depnds on the size of the file and how much you got room for on your disks.
Wondering Why,
if both file sizes are 700 megs, you will need 2 blank CD's to burn, you won't have room for both, unless you compress the files and don't mind crappy quality by compressing them to save disk space.
Whats the size of your blank disks?!?