Estimated adult weight
How big will my puppy get?
Puppies grow at different rates depending on their size, and they reach a predictable share of their adult weight by a given age. This calculator uses those size-based growth curves — enter your puppy’s current weight, age in months and expected size, and it estimates the adult weight they’re heading toward.
This is an estimate, not veterinary advice. Mixed breeds, big-boned pups and early spay/neuter can shift the final size. Your vet can give the best guess from your puppy’s breed and frame.
Frequently Asked Questions
How accurate is a puppy weight predictor?
It’s a good ballpark, usually within 10–15% for purebred dogs, because puppies grow along fairly consistent size-based curves. Mixed breeds are harder to call, so treat the number as a guide, not a guarantee.
At what age do puppies stop growing?
Small breeds finish around 10–12 months, medium breeds by about a year, large breeds by 12–18 months, and giant breeds can keep filling out until 18–24 months.
How do I know if my puppy will be small, medium or large?
Breed is the best clue; for mixes, look at the parents’ size and your puppy’s paws and frame relative to its age. When unsure, your vet can estimate the size category.
Does spaying or neutering affect adult size?
Timing can slightly affect growth-plate closure and final height in some dogs. It’s one reason to follow your vet’s advice on when to spay or neuter, especially for large breeds.