At birth, a Labrador puppy from average parents and an average litter (6 puppies) weighs about 1 pound or less. During the first 8 weeks of its life the puppy gains about 2 pounds a week. An 8 week old Labrador puppy weighs between 11 and 17 pounds. From 8 weeks to 26 weeks (6 months) this growth proceeds in about the same way - an average six month old Labrador weighs between 50 and 60 pounds. Dogs are heavier than bitches. After the age of 26 weeks the growth slows down. When your Labrador is one year old, the weight will be 65 to 80 pounds for dogs and 55 to 70 pounds for bitches. Between the age of one year and three years they gain another 5 to 10 pounds.