If you have small chickens/bantams, you could make 3 nests, but if your chickens are the larger, standard size you might want to stick with just 2 nests. I've heard that 14" wide is a good width for the larger chickens - gives them room to turn around in. You only need 1 nest for every 4 hens and I'm guessing you don't have very many hens living in your coop, so the two nests should be plenty.
