It's a minimum of b 4 square feet per hen. 20 X would be 80. And 10 square feet of run as well. So that would be 200. Hope that helps." The learning center " has lots of good info on here too.
I have 30+ chcikens and they are in a 9x6 house, but they are always out, the only time they are in the house is to nest, roost, and if the weather is bad out.