My puppy is 15 pound and age is unknown how big will he get?

I got a puppy from some lady who can no long take care of him. She didn't know how old it was. It is blue heeler and German shepherd mixed. It is 15 pounds in weight. I want to know if you may know how old he is and how big he will get in his adult year. Thank you.

Well German shepherds are bug dogs and blue heelers are medium sized dogs so it will be a medium-to large-ish sized dog. To get a good idea on how big a dog is going to be look at their paws. If their paws are really big compared to the rest of their body it tells you it will become a big dog.

The best way to find out how old a puppy is is to visit a vet, they should give you an approx age. A blue heeler and german shepard mix should be a large dog, slightly shorter than your average german shepard, and maybe a little lighter than the average 75-90 lbs. Look at his paws, if they are awkwardly large, he's in the adolescent phase. If still small, in puppy phase. If they're large, but match, he is entering the adult phase.

This is, of course, a guess but he's probably about three months old (give or take a week or two) and he'll probably be 50-60lbs.