Dog Size Calculator — Estimate Adult Weight of a Puppy
Enter your puppy's current weight and age to estimate adult weight using a simple growth formula. It's a rough guide — breed matters most.
How accurate is this?
The calculator uses the common rule of thumb: adult weight ≈ current weight ÷ age in weeks × 52. It works best for small and medium breeds; large and giant breeds keep growing longer, and mixed breeds are less predictable. Your vet can track growth curves more precisely.
Size classes: toy under about 12 lb, small 12–25 lb, medium 25–50 lb, large 50–100 lb, giant over 100 lb.
Frequently Asked Questions
How big will my puppy get?
Use the estimator for a rough range, and also look at the parents' sizes and the breed standard.
When do dogs stop growing?
Small breeds usually finish growing by about 12 months, while large and giant breeds can take 18–24 months.
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Results are estimates for general guidance and do not replace advice from a qualified veterinarian.