My sister had a Great Pyrenees. They are big dogs. The one she had, “Bubba”, was easily over a hundred pounds. He could put his front paws on my shoulders and lick me in the eye. And I’m 6’3”.
The Great Pyrenees I have seen that were herd guards were all around 150 lbs (not fat), or more. Usually male. I would assume a 100 pounder to be a youngster or a female.
Greatest family dogs ever. They used to herd my little brother back into the living room when he would try to "escape."