Biology

Puppy Adult Size Predictor

Estimate adult weight from puppy's current weight and age.

Predicting Puppy Adult Size

Puppies grow at different rates depending on breed size. Toy breeds reach adult weight by 8-10 months; giant breeds may grow until 18-24 months. Simple formula: Adult Weight ≈ Current Weight / (Age in weeks / Mature weeks). At 16 weeks, a medium-breed puppy is roughly 40% of adult weight. Other methods: double the weight at 16 weeks (medium breeds) or at 14 weeks (large breeds). Paw size relative to body is another rough indicator — big paws suggest more growing to do. For mixed breeds, weight at 6 months is approximately 2/3 of adult weight. These are estimates; genetics, nutrition, and health all influence final size.