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Puppy weight calculator
Enter your puppy's weight and age to see how big they're likely to get, plus a growth chart to the adult weight.
Your puppy's estimated adult weight, likely range and growth chart will show here.
Estimates only. Puppies of the same age and size can differ a lot. Last reviewed October 6, 2026.
How this calculator works
Puppies don't grow at a steady pace. They put on weight fast in the first months, then slow down as they approach adult size. How long that takes depends mostly on how big the breed is: toy breeds are close to adult weight by around 9 to 10 months, while giant breeds can keep growing until about 18 months or later.
The calculator uses a separate growth curve for each of five size classes. Each curve gives the share of adult weight a typical puppy of that size has reached at a given age. Your puppy's current weight divided by that share gives the estimated adult weight.
If you choose "Not sure", the calculator tries all five curves and keeps the one where the result fits the size class. Our curves are simplified approximations of the growth patterns described in published research on dog growth, including the growth standard charts for dogs of different sizes by Salt and colleagues (PLOS ONE, 2017).
Size classes used
| Size class | Adult weight | Example breeds | Growth mostly done by |
|---|---|---|---|
| Toy | Under 11 lb (5 kg) | Chihuahua, Yorkshire Terrier, Pomeranian | About 9–10 months |
| Small | 11–22 lb (5–10 kg) | Shih Tzu, Miniature Schnauzer, Pug | About 10–12 months |
| Medium | 22–55 lb (10–25 kg) | Border Collie, Cocker Spaniel, Bulldog | About 12–13 months |
| Large | 55–99 lb (25–45 kg) | Labrador Retriever, Golden Retriever, German Shepherd | About 15 months |
| Giant | Over 99 lb (45 kg) | Great Dane, Mastiff, Saint Bernard | About 18–21 months |
Why the result is a range
Two puppies of the same breed, age and weight can end up several pounds apart. Genetics, sex, diet and neutering timing all play a part. The range is narrower for older puppies, because more of their growth is already behind them.
If your puppy stops gaining weight, loses weight, or looks very thin or round compared with others of the same breed, ask your vet. Weight alone doesn't tell you whether a puppy is healthy; your vet can check body condition by feel.
Questions people ask
How accurate is a puppy weight calculator?
It gives a reasonable estimate, not a guarantee. Expect most puppies to land within the range shown. Results are more reliable for older puppies and for purebred dogs whose adult size is well known.
When do puppies stop growing?
Most small and toy breeds reach adult weight between 9 and 12 months. Medium breeds take about a year, large breeds 12 to 15 months, and giant breeds 18 months or longer. Many large dogs keep filling out with muscle for a while after they reach full height.
Can I use this for a mixed-breed puppy?
Yes. Choose "Not sure, work it out for me" and the calculator will pick the size class that fits your puppy's weight and age. If you know the parents' sizes, choosing that size class usually gives a better estimate.
Do paw size and the "double at 6 months" rule work?
Big paws are a popular sign of a big dog, but they are not a reliable predictor. Simple rules like doubling the weight at 6 months fit some large breeds reasonably well and miss badly for small and giant breeds, which is why this calculator uses a separate curve for each size class.
How often should I weigh my puppy?
Every one to two weeks while they are growing is enough to spot a problem early. Weigh at the same time of day, ideally before a meal, and enter the newest weight here to update the estimate.
Are male puppies bigger than females?
In most breeds adult males are somewhat heavier than females. If your puppy is a male of a breed with a wide weight range, expect a result toward the top of the range; for a female, toward the bottom.