How big does a dog need to be to be considered a giant breed?
Giant dog breed
Many giant breeds are mature, soft and relaxed dogs as adults and require less exercise than most smaller dogs, so they can make better pets for small living arrangements, such as apartments. Because they are larger animals, they are less likely to be intimidated by other people and thus are much more adaptable to meeting friends, family members, and children of owners.  They are normally very calm and are great family dogs. If they sense a threat towards their owner, they will become very protective. They are, in general, stronger than other breeds and many giant breeds are well known for their working abilities.[2]