Puppy size guide
How big will my puppy get?
See the adult height and weight range for your puppy's breed, or a size group for a mix, and when it usually stops growing.
Weigh-in log
Saved only in this browser. It shows how your puppy is tracking; it is not a growth assessment. For that, ask your veterinarian.
No weigh-ins yet.
Choose your puppy's breed, or the size group you expect for a mix, and see the adult height and weight range for that breed and roughly when it stops growing. The ranges come from the American Kennel Club's breed standards and breed pages, so they describe the breed as a whole: your puppy may land anywhere in the range, or a little outside it.
Most people use a number like this for something practical: choosing a crate, a harness or a carrier, or checking a housing weight limit before a conversation with a landlord. A range is enough for that kind of planning.
How the size guide works
Pick a breed to see its adult height and weight from the AKC breed standard or breed page, by sex or variety where the source gives them, in pounds and kilograms. For a mixed-breed puppy, pick the size group you expect instead. Either way, the guide also shows the age range when dogs of that size usually reach adult weight.
The guide shows ranges, not one number, because breed standards describe a range and individual dogs vary with sex, genetics, nutrition and health. It is not a diagnosis, a feeding plan or a guarantee of final size.
You can also keep a simple weigh-in log in this browser to see how your puppy is tracking. For a growth check against real growth curves, your veterinarian can use WALTHAM's puppy growth charts, which recommend three measurements two weeks apart, starting after 12 weeks.
When does a puppy reach adult size?
It depends on how big the dog will be. Small dogs finish early, and giant dogs keep growing well past their first birthday. These are typical ranges, and individual dogs vary with breed, sex, nutrition, health and body condition.
| Size group | Usually at adult size by |
|---|---|
| Toy or extra-small | 6 to 9 months, sometimes 8 to 12 months |
| Small | 8 to 10 months, generally by about 12 months |
| Medium | Up to about 12 months |
| Large | 12 to 18 months |
| Giant | 18 to 24 months |
For its maturity guidance, the Purina Institute counts toy dogs as under 6 kg, small dogs as 6 to 10 kg, medium dogs as 10 to 25 kg, large dogs as 25 to 45 kg and giant dogs as over 45 kg. Here, "adult size" means adult body weight, not full emotional or skeletal maturity. Your puppy may reach its final weight and still act like a puppy for a while.
Why quick rules of thumb miss, and how wide the range really is
You may have heard that a puppy doubles its 16-week weight by adulthood. It is easy to repeat and easy to remember, but growth is not a straight line. A 16-week-old toy dog is much closer to its final weight than a 16-week-old large-breed puppy, so one multiplier cannot fit both.
A better approach follows growth curves by expected adult size. A study of more than 6 million young dogs from Banfield Pet Hospitals in the United States showed that growth after weaning can generally be modeled by adult-size category rather than breed by breed. A follow-up validation study found that fewer than 5% of healthy dogs crossed more than two centile lines on those charts.
Those charts are the right tool for checking a growing puppy, and they work best with your veterinarian and several weigh-ins over time. A single weight on a single day says much less, especially for giant breeds, for mixed breeds and when the exact age is a guess.
Mixed breeds, paw size and DNA tests
For a mixed-breed puppy, the most useful input is the likely size group. If you know one or both parents' sizes, start there. If you adopted from a shelter or rescue, ask what size range the staff expect, and remember that an age listed on paperwork is often an estimate too. Pick that size group in the guide.
Paw size is a popular guess, and it does show something real about frame and breed type. It is not a measured method with a known error range, though, so we would not buy a crate on the strength of big paws alone. The likely size group and repeated weigh-ins tell you more.
A DNA breed test can help you choose a size group by showing which breeds are in the mix. Its accuracy figures describe breed identification, not adult weight, so a result helps you choose a size group in the guide but cannot name your dog's final weight.
When to ask a veterinarian
Normal puppies grow at slightly different speeds, and most owners never need more than a calm second weigh-in. Still, bring your puppy to a veterinarian if it is ill, losing weight, or growing unusually slowly or quickly. The same goes for a puppy whose weight keeps moving across growth-chart lines, or whose growth pattern changes and stays changed. WALTHAM notes that crossing two or more centile lines may call for veterinary advice.
Ask for an individual assessment if you have a giant-breed puppy, since the standard charts may not cover a dog that big. Questions about feeding amounts or health belong with your vet too. We are not veterinarians, and this tool is not a medical one.
Where to go next
If the guide points to a small dog, our small dog breeds list shows how the daily routine differs from one breed to the next. If it points to a large dog, the large dog breeds list does the same for bigger dogs. Still choosing a breed? Try the breed selector to match your routine and space.
When your puppy's next weigh-in comes around, add it to the log and compare. Use the breed range for planning a crate, harness, carrier or housing conversation, and not as a lease or purchase guarantee.