If his body condition is good, then I wouldn't worry about the numbers. It's so easy to get hung up on that. I remember. My English Mastiff came to me at 5 weeks old as a foster. At 6 weeks she only weighed 6 pounds 9 ounces. She was tiny. Now, at five years old, she's around 130 pounds. A perfectly respectable size and weight for a female. If you aren't sure about body condition, post some pictures that are taken from above while he's standing, from the side. And some of his face. And puppy feet. Lol. We love pictures. Welcome to the forum.