Puppy Growth by Week: What to Expect and Track

You will not find a reliable week-by-week weight chart for puppies, and any site that hands you one is guessing. The real veterinary science behind puppy growth exists as centile curves your vet plots from your puppy's actual weigh-ins, not a fixed table you can look up. This guide covers what the research does confirm, how vets actually track growth, and how to build your own record at home.

Why there's no universal week-by-week chart

The largest study of canine growth, Salt et al. 2017 in PLOS ONE, analyzed bodyweight records from more than 6 million young dogs and built growth standard charts using the same statistical method behind the WHO's child growth charts. The study sorts dogs into five adult-weight categories, from under 6.5 kg (about 14 lb) up to 40 kg (about 88 lb), and plots centile curves for each one from 12 weeks to 2 years old.

Here is the catch: the actual centile values in that paper, and in the related WALTHAM puppy growth charts built from the same 6-million-measurement dataset, are published only as chart images. There is no extractable numeric table of "week 8: X pounds" behind them. The charts work by tracking, not lookup. A vet weighs your puppy three or more times, finds which centile line those weights follow, and projects that line forward to see where it will flatten out. That is also exactly what your vet is doing when they plot your puppy's weight at each visit, and it is the most accurate version of this exercise you can get, because it uses your puppy's actual data instead of a breed average.

The two verified checkpoints

Two specific age-and-weight anchor points hold up to direct sourcing, both describing the same broad pattern: small dogs finish growing fast, big dogs finish growing slow.

• A toy breed puppy reaches about 50% of adult weight around 12 weeks old.
• A giant breed puppy reaches about 50% of adult weight around 26 weeks old.

These figures come from a commercial puppy weight calculator that cites the same growth research base, not from the primary veterinary papers directly, so treat them as a directional anchor rather than an exact prediction for your dog. No comparable verified figure exists for small, medium, or large breeds at any specific week, which is the same table gap described above.

The 4-month doubling rule, and its limits

Wisdom Panel's veterinary team describes a simple shortcut: multiply your puppy's weight at 4 months by two to estimate adult weight. A 15 lb puppy at 4 months would land around 30 lb as an adult.

Wisdom Panel itself flags this as the least accurate of the estimating methods it covers, because it ignores how much growth speed varies by size. Toy and small breeds mature fast and are closer to their adult weight by 4 months, so doubling their weight tends to overshoot. Giant breeds mature slowly and are nowhere near halfway done at 4 months, so doubling their weight badly undershoots. Use this rule as a rough gut check, not a number to plan around, especially if your puppy looks like it could grow past 50 lb as an adult.

A related shortcut, linear extrapolation (adult weight equals current weight divided by current age in weeks, multiplied by 52), makes the same mistake in a different form. It assumes every dog finishes growing around 12 months, which fits medium breeds reasonably well and fails large and giant breeds outright, since their growth does not follow a straight line out to week 52.

Our puppy weight calculator uses your puppy's breed and current weight to give you a size-adjusted estimate instead of one flat multiplier.

When growth typically finishes by size

Multiple sources agree on the broad timeline, even without a week-by-week table:

• Toy, small, and medium breeds reach adult body size by around 9 to 10 months old, per a summary of Hawthorne et al. 2004, the study most often cited for this figure.
• Growth rate generally plateaus after 6 months across all sizes, and skeletal growth plates in these breeds typically close by 8 to 12 months, according to the MSD Veterinary Manual.
• Large and giant breeds take much longer. The same Hawthorne 2004 summary puts them at roughly 11 to 15 months to reach 99% of adult body size, while MSD and VCA Hospitals put full skeletal maturity in these breeds at 10 to 16 months.

That gap is the entire reason a single week-by-week chart cannot work across breeds. A week 20 weight that is nearly adult-sized for a Chihuahua represents barely half the journey for a Great Dane.

Track your puppy's curve, not a chart

Since the real tool here is centile tracking, you can build a rough version of it yourself.

Weigh your puppy on the same scale at roughly the same time each week, and write the number down alongside the date. Three or four data points let you see whether your puppy's growth is climbing steadily or has flattened out, which tells you far more than comparing a single number to a stranger's chart. Bring that record to your vet visits. They have access to the full centile curves from the Salt et al. dataset and can plot your puppy's numbers against them directly, which is the only way to get an actual percentile rather than a guess.

Weight alone does not tell you if your puppy is growing at a healthy rate for its frame. Pair it with a body condition check using the WSAVA's 9-point body condition scale. A score of 4 or 5 out of 9 is the target range: ribs easily felt with only a thin fat layer over them, a visible waist from above, and a slight abdominal tuck from the side. A puppy scoring 6 or higher is carrying extra fat that can strain developing joints, and one scoring 3 or lower may not be getting enough food to grow properly. Our dog food calculator can help you check whether your puppy's daily portions match its energy needs at its current weight and age.

Red flags worth a vet call

Growth that stalls for more than a week or two, a puppy that suddenly loses weight, a visibly swollen or painful belly, limping that does not resolve in a day, or a body condition score that keeps drifting toward either end of the scale are all reasons to call your vet rather than wait for the next scheduled visit. Rapid, uneven growth in large and giant breeds in particular is worth flagging early, since it has been linked to orthopedic problems later on.

FAQ

Is there an official puppy growth chart by week?

Not in table form. The primary research, Salt et al. 2017 and the related WALTHAM charts, publishes centile growth curves as chart images built from over 6 million puppy weight records, but the underlying week-by-week numbers are not published as an extractable table anywhere in the public research. Vets use the chart images directly, plotting your puppy's actual weights against them.

How much should my puppy weigh at 12 weeks?

It depends entirely on the breed's expected adult size. The one verified anchor point available is that toy breeds reach roughly 50% of their adult weight around 12 weeks old. A medium or large breed puppy at the same age has typically covered a much smaller share of its total growth.

When do puppies stop growing?

Toy, small, and medium breeds generally reach adult size by 9 to 10 months old, with growth plates closing around 8 to 12 months. Large and giant breeds grow much longer, often not finishing until 11 to 16 months, with some giant breeds still filling out past a year.

Does the "weight at 4 months times two" rule actually work?

It gives a rough estimate at best. Wisdom Panel, which describes the rule, notes it is the least accurate of the common estimating methods because it does not account for how differently toy, medium, large, and giant breeds grow. It tends to overshoot for small breeds and undershoot for large ones.

DogTally guides and tools are for information only and are not veterinary advice. Talk to your vet about your dog's health.