How big should my run be? Meghan July 30, 2018 19:25 Follow The coop's run space should be at least 5+ square feet per bird. Related articles How big should my coop be? How much roost space do I need? How many nest boxes do I need? How do you give a chicken a bath? Once I order my chicks, how long until I receive them? Comments 0 comments Please sign in to leave a comment.