I am not a expert on this but here is the way I understand this. If your going to free rang or have a run you can get by with 2 sq feet of floor space in this state where we don't get a lot of snow. Without having away for them to get out of the coop at all for long period of time you have to have at least 4sq ft per chicken. I myself go with the 2sq ft with a run that has 8 sq ft per chicken cause we do not get much snow or bad weather that keeps them inside for long. So with the 72sq ft you have you could run as many as 36 chickens if they ha way to get out of there. I would run 20 to 25 with a run of 300sq ft of run.
Does your current set up use the 2 sq ft and 8 sq ft per chicken right now? Do they seem to be content with that amount of space? We have plenty of room right now but as the chicks grow that we have, I'm afraid things might get a little snug while we decide who to keep and who to sell. They will be layers, not extremely heavy breeds with hopefully a few bantams in the mix if I can convince my husband they are worth keeping.
