When Do Dogs Stop Growing? Growth Timeline by Breed Size

Your puppy is growing fast—but when will they stop? Here's exactly when dogs reach full size by breed.

If you like this kind of honest, obsessive dog-behavior breakdown, there’s more of it over on the GREET Dog blog.

When Duke Stopped Being a Puppy

I got Duke when he was 8 weeks old.

He was tiny. 15 pounds of golden fluff, clumsy paws, and pure chaos.

At 3 months, he'd doubled in size. At 6 months, he was 50 pounds and still growing. At 9 months, 65 pounds. At 12 months, 70 pounds.

Then... he just kept going.

By 18 months, Duke was 75 pounds. His frame had filled out. His chest had broadened. He looked less like a gangly teenager and more like an actual adult dog.

But I kept wondering: When would he stop growing?

Every month, I'd measure him. Weigh him. Compare photos. Try to figure out if THIS was his final form, or if he had more growing to do.

Golden Retrievers are supposed to be "fully grown" by 12-18 months. But Duke didn't get the memo. He kept gaining weight—slowly—until he was almost 2 years old.

Finally, at 22 months, he plateaued. 78 pounds. That was it. He was done.

But the journey taught me something: Dog growth is more complicated than just "when do they stop."

Here's everything I learned about when dogs stop growing, how to tell if your puppy is done, and what to expect at each stage.

When Do Dogs Stop Growing? The Quick Answer

Short answer: It depends on their size.

But here's the nuance:

Dogs reach their full HEIGHT earlier than their full WEIGHT.

Most dogs:

• Hit full height by 9-12 months (when growth plates close)
• Continue "filling out" until 18-24 months (adding muscle, chest depth, weight)

So when people ask "when do dogs stop growing," the real question is: Growing in HEIGHT or growing in WEIGHT?

Let's break it down.

How Dogs Grow: The Science of Growth Plates

Dog growth isn't gradual and steady—it happens in stages, controlled by growth plates.

What Are Growth Plates?

Growth plates (also called epiphyseal plates) are areas of soft cartilage at the ends of long bones (legs, spine). They're where new bone tissue forms, allowing the dog to grow taller.

How they work:

1. Puppy is born with growth plates in all long bones
2. As the puppy grows, growth plates produce new bone cells
3. Bones gradually lengthen (dog gets taller)
4. When the dog reaches full height, growth plates "close" (cartilage hardens into solid bone)
5. Once closed, the dog can't grow taller anymore

When do growth plates close?

• Small breeds: 8-12 months
• Medium breeds: 10-14 months
• Large breeds: 12-18 months
• Giant breeds: 18-24 months

Important: Growth plates close at different times for different bones. Leg bones usually close before spine bones, which is why some dogs look proportionally weird during adolescence.

When Do Dogs Stop Growing? By Breed Size

Let's break down growth timelines by size category:

Toy and Small Dogs (Under 20 lbs)

Examples: Chihuahua, Yorkshire Terrier, Pomeranian, Maltese, Shih Tzu, Toy Poodle

Full height: 6-10 months

Full weight: 10-12 months

Growth pattern:

• 0-3 months: Rapid growth (doubling/tripling weight)
• 3-6 months: Continue growing steadily
• 6-10 months: Reach full height, continue filling out
• 10-12 months: Fully grown

Key point: Small dogs mature fast. Most are essentially adults by their first birthday.

Medium Dogs (20-50 lbs)

Examples: Beagle, Cocker Spaniel, Border Collie, Bulldog, Corgi, Springer Spaniel

Full height: 10-14 months

Full weight: 12-15 months

Growth pattern:

• 0-4 months: Very rapid growth
• 4-8 months: Continue growing, but slower
• 8-12 months: Reach full height
• 12-15 months: Fill out to full adult weight

Key point: Medium dogs are usually mostly grown by 12 months, but may continue bulking up slightly after that.

Large Dogs (50-90 lbs)

Examples: Labrador Retriever, Golden Retriever, German Shepherd, Boxer, Rottweiler, Doberman

Full height: 12-18 months

Full weight: 18-24 months

Growth pattern:

• 0-6 months: Extremely rapid growth
• 6-12 months: Growth slows, but still significant
• 12-18 months: Reach full height, still look lanky
• 18-24 months: Fill out—chest broadens, muscles develop

Key point: Large dogs like Duke often look fully grown at 12 months, but they’re not really done until closer to 2 years.

Giant Dogs (90+ lbs)

Examples: Great Dane, Mastiff, Newfoundland, Saint Bernard, Irish Wolfhound, Great Pyrenees

Full height: 18-24 months

Full weight: 24-36 months

Growth pattern:

• 0-8 months: Explosive growth
• 8-18 months: Continue growing steadily
• 18-24 months: Reach full height
• 24-36 months: Fill out—massive chest, muscle development

Key point: Giant breeds take the longest to mature. It’s not unusual for them to still look unfinished at 2 years old.

When Do Specific Breeds Stop Growing?

Since people search for specific breeds, here are some popular ones:

When Do Golden Retrievers Stop Growing?

Full height: 12-14 months

Full weight: 18-24 months

Adult weight: Males 65-75 lbs, Females 55-65 lbs

Duke hit full height around 13 months but didn’t reach final weight until almost 2 years.

When Do Labrador Retrievers Stop Growing?

Full height: 12-14 months

Full weight: 18-24 months

Adult weight: Males 65-80 lbs, Females 55-70 lbs

Labs and Goldens usually follow a really similar growth arc.

When Do German Shepherds Stop Growing?

Full height: 14-18 months

Full weight: 18-24 months

Adult weight: Males 65-90 lbs, Females 50-70 lbs

German Shepherds are often a little slower to mature than Labs and Goldens, especially the males.

When Do Small Dogs Stop Growing?

Full size: 8-12 months for most toy and small breeds

Examples:

• Chihuahuas: 9-12 months
• Yorkies: 9-12 months
• Pomeranians: 9-12 months
• Shih Tzus: 10-12 months

When Do Mixed Breed Dogs Stop Growing?

This is trickier because mixed breeds can be unpredictable.

General rule:

• Look at the parent breeds if you know them
• Estimate adult size from the parents
• Use the larger parent’s timeline as the safer guide

Example:

If your mixed breed is part Beagle and part Golden Retriever, expect them to finish somewhere in the 15-20 month range instead of assuming the small side wins.

Paw size rule of thumb:

Larger paws relative to body usually mean more growing left to do. Puppies really do grow into them.

At What Age Can You Tell How Big a Dog Will Get?

This is one of the most common puppy-owner questions for a reason.

Several ways to estimate adult size:

1. The 4-Month Rule

At 4 months, many puppies are about 50% of their adult weight.

Formula: Current weight at 4 months × 2 = Approximate adult weight

Example: Duke was 35 lbs at 4 months. 35 × 2 = 70 lbs estimated adult weight. He ended up at 78, so it was pretty close.

Accuracy: Better for medium and large breeds than for tiny or giant dogs.

2. The 6-Month Rule

At 6 months, many puppies are about 75% of adult weight.

Formula: Current weight at 6 months ÷ 0.75 = Approximate adult weight

3. Paw Size Method

Large paws relative to body = likely more growing ahead

Not scientific in a perfect way, but honestly still useful.

4. Parent Size Method

If you know the parents, use them.

That’s usually the best real-world clue, especially for mixed breeds.

How Much More Will a Dog Grow After 6 Months?

Depends heavily on their size category:

Duke at 6 months: 50 lbs

Duke at adult: 78 lbs

Growth after 6 months: 28 lbs

This is why large-breed puppies feel like they grow forever. Because honestly, they kind of do.

Do Dogs Grow Taller After 1 Year?

Most dogs: no.

Some large and giant breeds: maybe a little.

What usually happens after 12 months:

• Small/medium dogs: Done growing taller
• Large dogs: Mostly done, may add a tiny bit
• Giant dogs: May continue adding height into 18-24 months

What is still happening after 1 year:

• Chest broadening
• Muscle development
• Weight gain
• Head and skull maturing

Duke stopped really getting taller around 13 months, but the rest of him kept catching up for a long time after that.

How to Feed a Growing Puppy

Proper nutrition during growth matters a lot. Get it wrong, and you can create real skeletal problems—especially in big dogs.

General Puppy Feeding Guidelines:

What to feed:

• Small/medium breeds: High-quality puppy food for their size
• Large/giant breeds: Large-breed puppy food with controlled growth support

How much to feed:

• 0-3 months: 4 meals per day
• 3-6 months: 3 meals per day
• 6-12 months: 2 meals per day
• 12+ months: 1-2 meals per day

Important: Feed based on expected adult size, not just the tiny body currently standing in front of you.

When I’m trying to keep feeding simple and consistent during growth, I’d rather use something I already trust than overcomplicate it → Vital Essentials Dog Food

Large/Giant Breed Puppy Feeding (Critical)

Why it’s different:

Large and giant puppies grow so fast that they’re more prone to developmental orthopedic problems if you push growth too hard.

Key rules:

• Use large-breed puppy food
• Don’t overfeed
• Keep puppies lean
• Switch to adult food when appropriate

Red flags:

• Puppy gaining unusually fast
• Chubby body condition
• Limping or avoiding exercise

If joints and skeletal support are part of what you’re watching closely, this is one of the first places I’d look too → Nutramax healthy dog supplements

How to Exercise Growing Puppies Safely

The big rule: don’t overdo exercise on a growing body.

Too much forced exercise during growth can stress developing bones and joints.

The 5-Minute Rule:

Maximum structured exercise per day = 5 minutes per month of age, twice daily

Examples:

• 3-month-old puppy: 15 minutes twice daily
• 6-month-old puppy: 30 minutes twice daily
• 9-month-old puppy: 45 minutes twice daily
• 12-month-old puppy: 60 minutes twice daily

What counts as exercise:

• Leash walks
• Running
• Fetch
• Playing with other dogs

What doesn’t count the same way:

• Free play in the yard
• Training sessions
• Gentle indoor play

Activities to avoid before growth plates close:

• Running on hard surfaces
• Repeated jumping on and off furniture
• Agility training too early
• Long forced hikes
• Biking alongside you

For safer daily movement, better walks, and more control while they’re still in that awkward growing stage, I usually start here → Ruffwear Dog Harnesses

If your puppy is wild and under-stimulated but you’re trying not to overdo the physical side, this one connects naturally too → Why Do Dogs Dig?

Signs Your Dog Is Done Growing

How do you know when your dog has actually hit the end?

Signs growth is complete:

• Weight plateaus for 3+ months
• Body proportions finally look adult
• Paws no longer look oversized
• Chest and head have filled out
• Energy levels start feeling less chaotic
• Your vet confirms it

With Duke:

• His weight stayed steady for months
• His chest stopped broadening
• He stopped looking awkward
• His vet confirmed he was basically done

FAQs About Puppy Growth

Q: Can you stunt a puppy's growth?

A: Yes. Malnutrition, over-exercise, and some medical issues can affect growth. But normal feeding won’t magically make them bigger or smaller than their genetics.

Q: Does spaying/neutering affect growth?

A: Yes. Early spay/neuter can delay growth plate closure, which may make a dog slightly taller than they otherwise would’ve been.

Q: Why is my puppy's growth uneven?

A: Because puppies go through weird phases. Legs grow before chest. Paws look too big. Then the rest catches up.

Q: My puppy seems smaller than littermates. Will they catch up?

A: Not always. There’s normal variation inside litters too.

Q: Can I make my puppy grow faster?

A: No—and you shouldn’t try. Faster isn’t better, especially for larger breeds.

Q: When should I switch from puppy food to adult food?

A: Small/medium breeds around 12 months. Large breeds around 12-15 months. Giant breeds sometimes later.

Q: Will my puppy's paws shrink?

A: No. The rest of the puppy grows into them.

Q: How can I tell if my puppy is growing too fast?

A: Fast weekly gain, chunkiness, limping, or discomfort are all reasons to talk to your vet.

Q: Why do giant breeds take so long to mature?

A: Because the jump from puppy to full adult is massive. That kind of skeletal development just takes longer.

Q: Do male and female puppies grow at different rates?

A: Usually yes, a little. Males often end up bigger and take slightly longer to finish.

The Bottom Line on Puppy Growth

After watching Duke go from a 15-pound puppy to a 78-pound adult over nearly two years, here’s what I learned:

Growth is a marathon, not a sprint.

Small dogs are usually done fast. Medium dogs not long after. Large dogs like Duke? They can look grown way before they’re actually finished.

And even once the height stops, the rest of the dog keeps maturing. The chest broadens. The frame fills in. The awkward teenager look finally disappears.

The key takeaways:

• Growth timelines depend mostly on size
• Height stops before weight
• Nutrition and controlled exercise matter a lot
• Don’t rush growth
• Your vet is still the best reality check if you’re unsure

Enjoy the puppy phase, even when it feels chaotic and endless. One day you’ll realize they quietly became a dog right in front of you.

If you want more of these straight-up dog behavior breakdowns, there’s more on the GREET Dog blog. If you want the bigger picture behind what GREET is building, here’s About Greet Dog. And if you ever want to reach out directly, here’s the contact page.

Note: This article is based on veterinary research and canine development science. Always consult your veterinarian for guidance specific to your puppy. We're dog parents who research obsessively—not veterinarians.