Is this the total space they'll have available? To minimize picking, cannibalism, etc the conventional answer around here is to provide something like 10 sq ft outdoors (~13-14 sq feet total of indoors and outdoors) space per bird, so you're looking at something like 4-5 chickens before they start feeling real crowded. Fewer (that is, more space per chicken) is always better, except inside the coop in extremely cold winter areas where more space is *still* prolly better but you may need a way of blocking some of it off during the coldest weather.
I'm going to get 2 hens and a rooster to start off. I'm going to build a coop that will be outside the pen. It will be 5 ft by 5ft. If I decide to get more then I'm going to build a 20 by 20 run and a 10 by 10 coop..This will be my first time having chickens.