Tough question, huh? There is no right answer. As a guide, mine were 5 weeks on Aug.16th. The smallest was a girl who was 9 oz at birth and is 4 1/2 lbs. The largest boy now was 12 oz at birth and is 6 lb 3 oz. A lot depends on the birth weights too. If all the pups are extra small or extra large to begin with they may not be anywhere near the weights of mine.
Most of my puppies are born at 16oz. At 4 weeks usually about 6 lbs, then at 6 1/2 weeks about 10 lbs.
When they go home at 8 weeks they usually average 15 lbs.
My dogs average bottom standard for height and average 85lbs for males and 75 for females.
For reference,these are predominantly English show pedigrees.
I keep notes of weights and can give you a range for litters at 6 weeks. We are talking about average weights per litter and they range from 8 pounds 6 ounces to 11 pounds 10 ounces. All were healthy puppies. It should be no surprise that the litter in which the pups averaged 11 - 10 was a 2 puppy litter. The litter that averaged 8 - 6 was a 10 puppy litter.
Even though I keep track of weights, I don't get hung up on them. If the puppies are healty and growing, they are fine.
Sizes of adults in the family group, previous puppies growth, and bloodline would need to be known to make a better estimate. The more you know about the history, the more accurate the evaluation. The breeder should be able to give you this information.
I'm considering getting a puppy from a litter of 8. I only know the weights of the 2 pups I choosing from. At the 7 week mark: one is 9 1/2 lbs, the other is 10 lbs. Does that seem a little light to you? Sire is a well known, champion. Bitch is average sized, certainly not large.
Wondering what affects weight, size of litter...dominant vs less dominant pup...?