🐾 Puppy Weight Calculator

When Do Dogs Stop Growing?

Short answer: somewhere between about 9 months and about 2 years, and size class decides almost everything. A Yorkshire Terrier is finished before a Great Dane is three-quarters grown. The longer answer is more useful, because "stops growing" is really two separate events — the dog stops getting taller, then spends months more getting heavier — and most of the confusion online comes from mixing them up.

Typical ages by size class

The table below pairs the usual maturity ages with something you rarely see published: how much of the adult weight is still to come at the two milestones owners actually ask about.

Size class Adult weight Typically full-grown % grown at 6 months % grown at 12 months Weight still to come after 12 months
Toy under 4 kg (9 lb) about 9-11 months ~85% ~100% none
Small 4-10 kg (9-22 lb) about 10-12 months ~80% ~100% none
Medium 10-25 kg (22-55 lb) about 12-15 months ~70% ~97% ~3%
Large 25-45 kg (55-100 lb) about 15-18 months ~58% ~88% ~12%
Giant over 45 kg (100 lb) about 18-24 months ~49% ~79% ~21%

Approximate ranges. The maturity ages are the commonly published bands for each size class; the percentage columns are read off our puppy growth chart, which carries a ±15% uncertainty band. Individual dogs finish early or late — these are typical trajectories, not deadlines.

8–104 weeks (≈ 12 months)
Expected adult size class

Pick by the adult size you expect (parents are the best guide). Large: e.g. Labrador, Golden Retriever, German Shepherd.

Estimated adult weight (combined range)

30–40kg(66–88 lb)

Union of the two methods below. A range is the honest answer — no formula can predict one exact number for a growing puppy.

Method A: growth-fraction

30–40kg

At 52 weeks, large-class puppies are at roughly 88% of adult weight (approximate table, ±15%). Adult estimate = current weight ÷ fraction.

Method B: simple linear rule

30kg

(current weight ÷ age in weeks) × 52. Simple linear rule — least accurate for large and giant breeds, and it tends to overshoot for toys. Past 26 weeks it degenerates toward the current weight, so it is shown for comparison only and not folded into the combined range.

Growth stage:Filling outHeight growth is mostly done; large breeds typically finish filling out at about 15-18 months.

Estimate only — growth varies by breed, diet and genetics; two healthy littermates can end up at very different adult weights. Confirm anything that matters with your vet.

Preset to a one-year-old large-breed dog — change the age and size class to see how much growing is left for yours.

Three worked examples at the one-year mark

A large-breed dog at 30 kg on its first birthday

Large-class dogs are around 88% of adult weight at 52 weeks, so 30 ÷ 0.88 ≈ 34 kg, and with the ±15% band the honest answer is 30–40 kg (66–88 lb). Note what the simple linear rule does here: at exactly 52 weeks it returns the current weight, 30 kg, and declares the dog finished. It is wrong, and predictably so — that is the rule's built-in assumption, not an observation about your dog.

A giant-breed dog at 35 kg on its first birthday

Giant-class dogs are only about 79% grown at a year, so the same milestone means something completely different: 35 ÷ 0.79 ≈ 44 kg, banded to 38–52 kg (84–114 lb). A giant-breed owner who assumes "one year old = done" is off by roughly a fifth of the dog.

A small-breed dog at 5 kg at 8 months

Small breeds are around 90% grown at 34 weeks, so 5 ÷ 0.90 ≈ 5.6 kg — 5.0–6.5 kg (11–14 lb). At this point further weight gain should be small. If a small dog keeps gaining steadily past this age, the likely explanation is body condition rather than growth, which is a conversation for your vet.

Height stops before weight

Dogs reach their adult height when the growth plates in their long bones close, and that happens well before the dog is finished filling out. Growth-plate closure is commonly described as happening around 8–11 months in small dogs and as late as 18–24 months in giant breeds. After that, the dog is done getting taller but continues adding muscle and chest depth — which is why a 13-month-old large-breed dog can look adult-sized in a photo and still be a few kilograms short of its adult weight.

This gap explains most of the "my dog stopped growing but keeps gaining weight" questions. Both things are normal at the same time. It is also why the growth-fraction method on this site is based on weight rather than height: weight is the thing owners can actually measure at home, and it is the thing that keeps changing.

What can shift the timeline

  • Neutering timing. Removing sex hormones before skeletal maturity is associated in some studies with later growth-plate closure and a slightly taller adult dog. Effect sizes differ by breed and study, and there are other trade-offs in both directions — decide this with your vet, not with a chart.
  • Nutrition. Large- and giant-breed puppy foods exist because controlled growth matters for developing joints. Pushing a puppy to grow faster than its curve is not a neutral choice; slower, steadier growth is the conventional veterinary preference for big breeds.
  • Illness or parasites. A setback can flatten the curve for weeks, sometimes followed by catch-up growth after treatment.
  • Individual genetics. Littermates finish at different sizes. Nothing in any chart overrides which parents your puppy took after.

Common questions

Do dogs keep growing after 1 year?

Toy and small breeds usually do not — they are typically at adult weight by 9–12 months. Medium breeds are close to done. Large breeds commonly have around a tenth of their adult weight still to gain at 12 months, and giant breeds around a fifth, finishing anywhere up to 24 months.

At what age is a dog full-grown mentally?

Behavioural maturity typically lags physical maturity: many dogs are physically adult while still acting adolescent, and trainers commonly describe settling somewhere between 18 months and 3 years, later in big breeds. That is behaviour, not bone, and no weight calculator can measure it.

Can I tell from paw size?

Not reliably. Large paws on a young puppy loosely suggest more growth ahead, but there is no published paw-to-adult-weight formula. Weight at a known age, read against expected adult size class, is a far better signal — that is what the calculator above uses.

Where to go next

To see the full percentage-by-age table for every size class, use the puppy growth chart. For breed-specific expectations built on published breed-standard adult ranges, see Labrador puppy weight and Golden Retriever puppy weight. Or run your own numbers on the puppy weight calculator.

Everything here is an estimate — growth varies by breed, diet and genetics; confirm with your vet.