What size cat carrier should I get?

[Artemisblossom]

I am picking up my little Balinese kitten in August and am wondering what size of carrier should I have for her to come home in? She will be just 2 days shy of 12 weeks old. It is going to be about an 11 hour drive and thanks to the wonderful people on here I know that I need the carrier and a small litter pan.(and a few other things) I already have a couple carriers, one that a puppy came home in. It seems huge and I have a small one that my African Grey Parrot was shipped to me in. That one seems like it would be lots big enough for a kitten but I don't really know how big a 12 week old balinese is . Can someone give me a rough estimate of the size of their cat carriers?