Free puppy growth tool
How big will my puppy get, and is it on track?
Enter your puppy's breed, weight and age. We'll show the healthy weight range for its age, whether it's on track, and the typical adult size for the breed, using WALTHAM growth science. Built for puppies up to about 24 months.
Expected weight now
How big will it get?
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Get the puppy years right
It's great that you're tracking growth, the first year shapes a dog's whole life. Our free Longevity Guide covers how dogs develop, the foundations of healthy growth, and the habits that add years.
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Estimates are based on WALTHAM Petcare Science Institute size-category growth research and your breed's adult weight range. Individual puppies vary with genetics, neuter status, sex and nutrition, so treat this as guidance, not a diagnosis. Your veterinarian can confirm whether your puppy is growing healthily.
How the puppy growth estimate works
The WALTHAM Petcare Science Institute built growth standards from over 6 million weight measurements across 50,000 healthy puppies, the same way pediatric growth charts work for children. Puppies of each size category reach a predictable percentage of their adult weight at each age, so from your puppy's current weight and age we can show the healthy weight range for that age, check whether growth is on track, and show the typical adult size for the breed.
How big will my puppy get?
This is the question almost everyone is really asking, and the honest answer has two halves. The half nobody can give you is an exact adult weight: two littermates raised in the same house end up at different sizes, and neuter timing, nutrition and simple genetic luck all move the number. Any tool that hands you a single confident figure is dressing up a guess.
The half that is reliable is the range. Your breed has a published adult weight range, and puppies of each size category reach a predictable share of their adult weight at each age. That is why this page shows you the typical adult range for the breed rather than one made-up number, and shows where your puppy sits on the curve today. For a mixed breed, the larger parent gives you the safer upper bound.
Does doubling the four-month weight work?
It is the most repeated rule of thumb and it is only roughly right. It lands closest on medium breeds and it under-estimates large and giant ones, because bigger dogs keep growing for months after a medium dog has finished. A Golden Retriever at four months typically weighs 22 to 31 lb. Doubling that gives 44 to 62 lb, against the 55 to 75 lb these dogs actually reach: the rule lands low, and it lands lower the bigger the breed. Use the size category curve above rather than a single multiplier.
When puppies stop growing
Smaller dogs finish first: toy and small breeds are usually full-grown by 10-12 months, medium breeds by 12-14 months, large breeds by 14-18 months, and giant breeds keep developing until 18-24 months. Bigger dogs grow for longer, which is exactly why large-breed puppy nutrition matters.
Why growing too fast is a risk
In large and giant breeds, growing too quickly is linked to developmental joint problems like hip dysplasia. Steady, lean growth, not maximum growth, is the goal. See our joint health guide for the support side, and check your adult dog with the Dog Weight Checker.
Common questions
How big will my puppy get?
Expect a range, not a number. This page shows the published adult weight range for your breed and where your puppy sits on the growth curve for its size category today. Nobody can predict an exact adult weight, and a tool that gives you one is guessing.
Is doubling my puppy's four-month weight accurate?
Roughly, and mostly for medium breeds. It under-estimates large and giant breeds, which keep growing for months longer. The size category growth curve is the better guide.
How accurate is this weight check?
It's a guide, not a diagnosis. It's most reliable after about 12-16 weeks, once early growth has settled. Mixed breeds and unknown parentage add uncertainty. Your vet's body condition score is the final word.
My puppy is a mixed breed, what do I pick?
Pick the breed it most resembles, or the larger parent for a safer upper estimate. The size category drives the growth curve more than the exact breed.
Is my puppy underweight or overweight?
This tool compares your puppy to the expected weight for its age and breed. Below the expected band can mean a lean or smaller individual; well above can mean fast growth. Either way, confirm with a vet body condition score.
Where does the data come from?
The growth model uses WALTHAM Petcare Science Institute size-category growth research and your breed's published adult weight range. It is educational guidance, not a diagnosis.
