I would call it a Newborn size. This Blue Cocoon measures 27 inches long. It will stretch to around 12 inches wide. With it being 27 inches long leaves a lot of room for stretching and still have room to roll it down around the shoulders.The cocoon is made to keep a baby warm, not something that you would carry it around by as it may not hold his weight. The Hat is a newborn size but it will stretch also.