If you put them in at sundown and let them out early in the morning, they don't need that much room. It's like you going to bed at night. smile But if you figure you might occasionally be leaving them in during the daytime, then they'd need more room. I'd give them 5 sq' each for night time, and double or even triple that for an occasional daytime coop. If they were in there ALL the time, I wouldn't hesitate to say a pair of geese should have a minimum of 100sq' and up from there.