How big should five week old German Shepherds be?

At five weeks they would be slightly smaller than a housecat, but not by much. Remember that a large GSD is going to be 22 -26" as an adult (depending on sex)

Here is a breeder who documented the growth of the dogs for a year:

http://www.akcblackgermanshepherds.com/puppies.htm...

you can see the approximate size of the five week old pups.

5 month old shepherds would be MUCH bigger than a housecat. 5-8 weeks is around the size of a house cat if not smaller or slightly bigger.

when my shepherds were 5 weeks they were definitely not that big. They fit into an adult man's hand they were so small. That sounds like an accurate size for a 5 month old, not 5 week..