Allowing 1sq ft per bird would be a max of 32 but you have to account for lost sq footage to feeders, waterers, and other “furniture” so 20 would probably be max and you may find that 20 is too many depending on your preferences. In a cage production setting like myshire, he keeps 3-4 birds per sq foot without issue....so using that math you would max at 100ish in that size.whats the limit in a pen that size?