7 to 12 lbs, depending on the sex and the litter, for my puppies at 5 weeks. Boxers or APBT are quite a bit smaller tho, not to mention the rough start these little guys have had.
The Doberman puppies I've been helping out with averaged 6.5lbs when I weighed them at 5 weeks. Some a little more, some a little less. The smallest was 5 3/4lbs and the largest was 7lbs.