The size your puppy will grow to largely depends on its breed, genetics, sex, and age. Experts often use these common estimation methods:
- For small breeds, triple the puppy’s weight at 8 weeks.
- For medium and large breeds, double the puppy’s weight at 16 weeks.
- Another formula is (puppy weight / puppy age in weeks) × 52 to estimate adult weight in pounds.
- Knowing the size of the puppy’s parents also helps predict adult size.
- DNA testing can provide the most accurate prediction by analyzing genes associated with size.
Additionally, growth duration varies by breed size:
- Toy and small breeds reach their full size within 6 to 9 months.
- Medium breeds around 1 year.
- Large breeds can take 14–18 months.
- Giant breeds may take 2 to 3 years to reach full size.
Paw size and growth rate are sometimes used as rough indicators, but they are less precise than weight-based calculations or genetic information. Following your puppy’s weight and age, and ideally knowing breed or parent size, helps make the best estimate of adult size.
