The weight of a 4-month old Lab puppy depends on several factors, but it should be around 40 pounds. This weight varies by each dog and its lifestyle.
Lab puppies usually weigh around 11 to 17 pounds at eight weeks and gain an average of 2 pounds per week for the next several weeks. The exact weight depends on how much the puppy is eating and how much exercise it gets. The parents' build and weight also factor in, with some puppies being leaner and others leaning towards a stocky build. Feeding a puppy the correct amount of puppy food for its age helps ensure the correct body weight. Avoid feeding table scraps and too many treats to keep the puppy from being overweight. Puppies also need a lot of exercise to burn off excess calories.