The average weight of a four-month-old Labrador puppy is between 37 and 43 pounds. Male dogs are usually heavier than females. There are many different types of Labradors, and each one has different weight profiles.
When a Labrador puppy is born, it weighs approximately 1 pound or less. In the first eight weeks of the dog's life, the dog gains around 2 pounds a week. When the puppy is eight weeks old, it should weigh between 11 and 17 pounds. The growth process continues with the puppy gaining about 2 pounds per week until it reaches the age of 26 weeks. At this age, its weight gain rate slows.