I currently have a coop that's a bit over 100 sq ft. I currently have 26 chickens in total: 23 hens and 3 roosters. There is a main door into the coop and a large cut out (like a dog door but with no flap) for them to go outside in. The area outside, where they spend most of their time is huge. If I remember correctly it's in the range of 200+ linear feet with an electrical fence outside of the regular fence to keep predators out. The chickens can NOT get to the electrical fence so there's no danger to them. Inside the coop I have 2 metal 6 count nesting box raised above the ground and a 10' 2x4 for them to perch on at night to sleep. I would guess about 18 chickens (maybe more) using the 2x4 for sleeping at night. The others have corners that they cuddle into with others at night. I thought about increasing the amount of chickens we have in the spring. As far as how many I'm not sure. Thoughts?