An American Bulldog Pitbull mix can grow to be quite large – up to around 30 inches at the shoulder and weighing in at around 100 pounds. However, size will vary depending on which parent breed your dog takes after more. If your dog takes after the American Bulldog side, they may be slightly smaller than if they take after the Pitbull side. Either way, you can expect a medium to large sized dog that is muscular and powerful.