What should a puppy weigh at each age? A puppy grows fast, and its weight changes every few weeks — so the answer is not a single number, but a chart: the expected weight at each age, as a share of the puppy's expected adult weight. This guide is that chart in words, plus how to use it, how to weigh a puppy, and when a puppy that is off the chart needs a vet. Every figure is a very rough guide, because individual dogs vary widely, and the chart is a starting point for a conversation with your vet — not a verdict on your puppy.
The short version is: weigh the puppy every two weeks, compare with the breed's expected adult weight, and look for a smooth, steady rise — not a flat line and not a sudden jump. As a very rough guide, a puppy's weight as a share of its expected adult weight is about a fifth to a quarter at 8 weeks, about a quarter to a third at 3 months, about a third to two-fifths at 4 months, about half to two-thirds at 6 months, about three-quarters to four-fifths at 9 months, and about four-fifths or more at 12 months, when small breeds are near-adult and large breeds are still growing. The puppy weight predictor estimates adult weight from the puppy's current weight and age, and the puppy weight calculator by breed size guide explains how to track growth against the breed's expected adult weight.
Puppy weight chart by age
The table below gives the expected adult weight by size, and the very rough weight at 8 weeks and at 6 months for each size. The 8-week and 6-month figures are rough shares of the adult weight, not measurements from a study of individual breeds — use them to check whether your puppy is broadly on track, not to judge it to the gram.
| Size | Expected adult weight | Weight at 8 weeks (very rough) | Weight at 6 months (very rough) |
|---|---|---|---|
| Toy | 1–5 kg | About 1–2 kg at 8 weeks (very rough) | About 1–3 kg at 6 months (very rough) |
| Small | 5–10 kg | About 2–3 kg at 8 weeks (very rough) | About 3–6 kg at 6 months (very rough) |
| Medium | 10–25 kg | About 3–6 kg at 8 weeks (very rough) | About 6–15 kg at 6 months (very rough) |
| Large | 25–40 kg | About 6–9 kg at 8 weeks (very rough) | About 15–24 kg at 6 months (very rough) |
| Giant | 40–90 kg | About 9–19 kg at 8 weeks (very rough) | About 24–54 kg at 6 months (very rough) |
Read the table from left to right and the pattern is clear: a puppy grows fastest in the first few months, then slows down towards the end of its first year, and large and giant breeds keep growing long after small breeds have finished. A puppy that is well outside the rough share for its age — much heavier or much lighter than the table suggests — should be checked by a vet, rather than having its food changed on your own.
How a puppy's weight changes as it grows
A puppy does not grow evenly: it grows fastest in the first few months, then slows down towards the end of its first year. In the first weeks, a puppy should gain weight every day — a newborn puppy that is not gaining weight needs a vet check, not just more food. By 8 weeks, a puppy is about a fifth to a quarter of its expected adult weight. By 3 months it is about a quarter to a third, by 4 months about a third to two-fifths, by 6 months about half to two-thirds, by 9 months about three-quarters to four-fifths, and by 12 months about four-fifths or more, when small breeds are near-adult and large breeds are still growing.
Those shares are very rough, and individual dogs vary widely — a puppy that is a little above or below the share for its age is usually fine, as long as it is gaining weight steadily and is bright, eating, and active. What matters is the line over weeks: a smooth, steady rise. A puppy that is not gaining weight at all over two weeks, or that is losing weight, needs a vet check. A puppy that is gaining weight in sudden jumps may be overfed, and a puppy that is gaining weight very slowly may be underfed or unwell — either way, the vet is the right next step, not a change in food on your own.
How to weigh a puppy and track its growth
Weigh the puppy every two weeks, at the same time of day, on the same scales, and write the number down — the line over weeks is what matters, not any single reading. For a small puppy, step on the bathroom scales holding it, then step on without it, and take the difference. For a larger puppy, use the vet's scales at a routine visit. Plot the weights on a simple chart, or just keep a list with dates: what you are looking for is a smooth, steady rise, not a flat line and not a sudden jump.
Feel the ribs at every weigh-in: you should feel them easily under a thin layer of fat, and see a waist from above and from the side, even in a puppy. A puppy that is too fat is not a healthy puppy: excess weight in youth sets up weight problems for life, and in a large-breed puppy it strains developing joints. A puppy that is too thin is not a healthy puppy either: it may not be getting enough food, or it may be unwell. The table above gives the rough shares; the scales and your hands tell you whether the puppy is on track. The how much food should a puppy eat per day by weight guide gives the calorie tables by weight, and the how often should you feed a puppy guide gives the feeding schedule.
When a puppy's weight needs a vet
See a vet promptly if the puppy is not gaining weight over two weeks, if it is losing weight, if it is much heavier or much lighter than the rough share for its age, if it is lethargic or off its food, or if it has vomiting or diarrhoea. A puppy that is not growing needs a vet, not just more food — parasites, infections, and other problems can all slow growth, and they need treating. Bring the weight record: a list of weights with dates is far more useful to a vet than a single number, because it shows the line over weeks.
At the vet, expect a weigh-in, a check of the puppy's body condition, and questions about food, feeding times, and other pets in the house — and possibly a stool sample, because parasites are a common cause of slow growth in young animals and are easy to treat. Do not try to make a puppy grow faster with extra food: rapid growth and excess weight strain developing joints, and in a large-breed puppy that matters more than in a small one. The puppy too skinny — what to do guide covers a puppy that is too thin, and the how much should a puppy eat guide gives the calorie tables.
Common mistakes with puppy weight
The most common mistake is weighing too rarely: a puppy grows fast, and a puppy weighed once a month is already being weighed too rarely — weigh every two weeks. The second is judging by a single reading: a puppy that is a little above or below the chart on one day is usually fine, and the line over weeks is what matters. The third is overfeeding to make the puppy grow faster: rapid growth and excess weight strain developing joints, and in a large-breed puppy that matters more than in a small one. The fourth is underfeeding a puppy that is growing fast, because the owner is afraid of overfeeding: a puppy that is not gaining weight needs a vet check, not a smaller portion.
The fifth is comparing puppys of different breeds or sizes: a large-breed puppy at 6 months weighs far more than a small-breed puppy of the same age, and both are normal for their size. Compare your puppy with its own breed's expected adult weight, not with another puppy of a different size. The puppy growth chart by breed size guide gives the growth tables by size, and the when is a dog fully grown guide gives the growth ages by size and breed.
For related reading, see the puppy weight predictor, the puppy weight calculator by breed size guide, the how much food should a puppy eat guide, the how often should you feed a puppy guide, the puppy too skinny — what to do guide, the when is a dog fully grown guide.
Frequently asked questions
How much should a puppy weigh at 8 weeks?
As a very rough guide, about a fifth to a quarter of its expected adult weight. A puppy that will be 10 kg as an adult is roughly 2 to 2.5 kg at 8 weeks, and a puppy that will be 30 kg as an adult is roughly 6 to 7.5 kg. Those are rough shares, not measurements — individual dogs vary widely, and the line over weeks matters more than any single reading.
How much should a puppy weigh at 6 months?
As a very rough guide, about half to two-thirds of its expected adult weight. A puppy that will be 10 kg as an adult is roughly 5 to 6.5 kg at 6 months, and a puppy that will be 30 kg as an adult is roughly 15 to 20 kg. Small breeds are nearer adult at 6 months than large breeds, which keep growing for longer.
How often should I weigh my puppy?
Every two weeks, at the same time of day, on the same scales, and write the number down. A puppy grows fast, and the amount of food changes quickly, so a puppy weighed once a month is being weighed too rarely. Plot the weights on a simple chart, or keep a list with dates.
My puppy is not gaining weight — what should I do?
See a vet promptly. A puppy that is not gaining weight over two weeks, or that is losing weight, needs a vet check — parasites, infections, and other problems can all slow growth, and they need treating. Do not just feed more: a puppy that is not growing needs a vet, not just more food.
Can a puppy be overweight?
Yes — a puppy that is too fat is not a healthy puppy. Excess weight in youth sets up weight problems for life, and in a large-breed puppy it strains developing joints. Feel the ribs at every weigh-in: you should feel them easily under a thin layer of fat, and see a waist from above and from the side, even in a puppy.
When is a puppy fully grown?
Small breeds finish growing at about 9 to 12 months, medium breeds at about 12 months, large breeds at about 12 to 18 months, and giant breeds at 18 months to 2 years. For cats, most breeds finish at about 12 months, but large breeds such as the Maine Coon can keep growing until 2 to 4 years.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.