When Do Puppies Stop Growing? Age Chart by Size and Breed

When do puppies stop growing? The honest answer is “it depends on how big they’ll be”. Small dogs race to adulthood in under a year; giant breeds take nearly two. VCA puts it simply: small and medium breeds reach adult size at about 10–12 months, and large and giant breeds can keep growing until 18–24 months.

Below is a month-by-month chart by size, what “done growing” really means, and a worked example with our puppy weight calculator.

Puppy growth chart: when each size stops growing

Our calculators use growth curves based on Salt et al. (2017), who built growth standards from the vet records of more than 6 million dogs, the same way pediatric growth charts are made. Here is when a typical puppy in each size group reaches 90%, 95% and 99% of its adult weight:

Size group (adult weight)	Example breeds	90% grown	95% grown	Essentially adult (99%)
Toy (under 14 lb)	Chihuahua, Yorkie, Pomeranian	~7 months (30 wk)	~8 months (36 wk)	~11 months (48 wk)
Small (14–20 lb)	Shih Tzu, Miniature Schnauzer	~7½ months (33 wk)	~9 months (40 wk)	~11 months (49 wk)
Medium (20–33 lb)	Beagle, Cocker Spaniel	~8 months (36 wk)	~10 months (44 wk)	~13 months (58 wk)
Large (33–66 lb)	Aussie Shepherd, Boxer, Husky	~10 months (43 wk)	~12 months (52 wk)	~15 months (65 wk)
Extra large (66–88 lb)	Labrador, Golden, German Shepherd	~11 months (49 wk)	~14 months (60 wk)	~17 months (74 wk)
Giant (over 88 lb)	Great Dane, Mastiff, Newfoundland	~13 months (58 wk)	~16 months (68 wk)	~21 months (91 wk)

Weeks are from our calculator’s growth curves, read from the Salt et al. 2017 / WALTHAM median lines. Those standards stop at 40 kg (88 lb), so the giant row is our extrapolation. Individual dogs vary.

The pattern matches VCA’s guidance: the small groups are done before their first birthday, and the biggest dogs take well into their second year.

What does “stopped growing” actually mean?

Growth doesn’t switch off on one day. Three things finish at different times:

1. Height. Most puppies get close to their adult height first. After that, the bones are still maturing even if the dog doesn’t look taller.
2. Skeleton. The 2021 AAHA nutrition guidelines say large and giant breeds reach skeletal maturity at about 15 to 16 months. Until then, growth diets and careful portions matter.
3. Weight and muscle. Dogs keep “filling out” for months after they stop getting taller, especially deep-chested and giant breeds. That’s why the 99% column runs later than most owners expect.

Worked example: when will a Labrador puppy stop growing?

Your Labrador puppy is 16 weeks old (about 4 months) and weighs 20 lb. In the puppy weight calculator, enter 20 lb at 16 weeks and choose the extra-large group (66–88 lb adults, which includes most Labradors).

At 16 weeks an extra-large puppy is typically at about 37% of adult weight. The calculator predicts:

• Adult weight: about 54 lb, with a likely range of 48–61 lb
• 90% of adult weight: at about 49 weeks (11 months), roughly 49 lb

The prediction came out lighter than the breed’s typical 66–88 lb, so it suggests this pup may land in the large group instead. That’s common with field-line Labradors and mixes. Re-weigh every couple of weeks and plot the numbers on the puppy growth chart: if the dots track one line, you’ll know which group your puppy really belongs to. Our guide on how big your puppy will get covers the other ways to estimate adult size.

Why do big dogs take longer to grow?

A Great Dane puppy and a Chihuahua puppy are born at very different weights, but the gap at adulthood is far bigger, so the giant puppy has much more growing to do. It does that by growing for longer, not just faster. That long growth phase is also why large-breed puppies need a food labeled for large-breed growth and measured portions: too many calories push growth faster than the bones and joints can handle.

How should feeding change as growth slows?

• Meals. VCA recommends portion feeding a set amount two to three times a day for growing puppies. Our post on how often to feed a puppy has a feeding chart by age and weight.
• Calories. As growth slows, calories per pound drop. The puppy food calculator switches from 3 × to 2 × resting energy at about 4 months (the Merck factors) and flags puppies that are nearly grown.
• Treats. Keep them under 10% of daily calories (VCA).
• Switching to adult food. Switch when growth is nearly done: around 10–12 months for most small and medium dogs, and later for large and giant breeds. Your vet can confirm.

Growing dogs also outgrow crates fast. If you’re buying a crate now, our post on how long a puppy can stay in a crate and the crate size guide explain how to size for the adult dog and use a divider.

How do I know if my puppy is growing normally?

Weigh your puppy every 1–2 weeks and plot it. Salt and colleagues’ 2020 follow-up study compared growth in healthy dogs and dogs in abnormal body condition, and found their growth patterns differed, which is why the trend matters more than any one weigh-in. A puppy that climbs steeply across lines may be eating too much; one that drops across lines may not be getting enough, or may be unwell. If you don’t know your puppy’s exact age, start with how to tell how old a puppy is.

When to call your vet

Talk to your vet if your puppy:

• stops gaining weight for more than two weeks, or loses weight
• crosses two or more lines on the growth chart, up or down
• limps, has swollen joints or seems reluctant to play (especially large breeds)
• looks pot-bellied with thin limbs, or has ongoing diarrhea
• is much smaller than littermates and seems tired or weak

Bring your weight log to the visit. A simple list of dates and weights helps your vet judge growth far better than a single weigh-in.