If you’re wondering when your dog will stop growing, you’re not alone — growth can look very different depending on breed, size, and overall health. Here’s how to estimate your dog’s “done growing” point, what’s normal, and when it’s worth checking in with a vet.
Need to Know
Our editorial team reviewed the best-available pet guidance and community owner reports to answer this. Most dogs stop getting taller (skeletal growth) before they stop “filling out” (muscle and body condition), so it’s normal for a dog to look more mature after height has stabilized. Breed size is the biggest driver: small dogs often finish sooner, while large and giant breeds can keep developing well into young adulthood, as described in AKC guidance and in peer-reviewed veterinary journals.
Quick Answer
Most dogs stop their main skeletal growth between about 6–24 months, depending largely on adult size: small breeds often finish earlier, medium breeds around the first year, and large/giant breeds may not be fully done until closer to 18–24 months (with “filling out” continuing longer).
What This Usually Means
When people ask “when do dogs stop growing,” they’re usually noticing one of three things: your puppy’s height seems to have plateaued, your dog’s weight is still climbing, or your dog looks awkwardly leggy and you want to know when the proportions will even out. It helps to separate growth into two buckets: skeletal growth (bone length/height) and maturation (muscle, chest width, head shape, and overall body composition). A dog may be “done growing” in height but still look like they’re changing for months afterward.
In general, smaller dogs finish sooner and bigger dogs finish later. Toy and small breeds may be close to adult height by around the middle of the first year. Many medium dogs are near adult size around a year. Large and giant dogs can take longer because their growth plates typically close later, and their overall maturation takes longer. The AKC frequently notes size-related differences in development timelines, and veterinary references commonly discuss later growth plate closure and extended adolescence in large breeds.
There’s also real-world uncertainty in predicting adult size — especially for mixes. Shelter or rescue estimates can be off because lineage is unknown and early growth spurts aren’t perfectly predictive. You may see a period where growth slows after the first year, but it doesn’t necessarily stop abruptly; it can taper gradually, then shift from “up” to “out” as the body develops muscle and adult proportions.
“Growth is a curve that flattens out as a puppy reaches full growth. A lot of when a dog finishes growing depends on the breed. My pup has finished growing however he’s still putting on weight because he is filling out (muscle mass.) I don’t expect to see him at his final weight…”
r/puppy101
What Can Help
- Track growth in a simple, consistent way. We’d use the same scale when possible, weigh at the same time of day, and take a quick monthly photo from the side. Patterns (slowing, plateauing, sudden jumps) matter more than any single weigh-in.
- Know what “done growing” looks like for your dog’s size. A small dog that hasn’t changed height in weeks may truly be near adult height, while a large-breed adolescent might pause and then hit another slower growth phase. Your vet can help you interpret what’s typical for the breed type and expected adult size.
- Ask your vet about growth plates if you’re unsure. If it’s important to know whether your dog is finished with skeletal growth (for example, before certain high-impact sports or evaluating limping), a vet can discuss whether imaging is appropriate and what it would tell you.
- Feed for the life stage and expected adult size. Growth is tightly tied to nutrition. We’d prioritize a diet formulated for puppies (or large-breed puppies when appropriate), and we’d avoid overfeeding in hopes of “helping them grow”—rapid weight gain can stress developing joints.
- Use body condition, not just pounds, to judge development. A dog can gain weight from muscle “filling out” or from excess fat. Your vet can show you how to assess body condition and adjust portions so growth stays steady and healthy.
- Keep exercise age-appropriate. Regular movement supports healthy muscle development, but repetitive high-impact work (like constant jumping from heights) may be a poor fit for dogs still growing. We’d aim for controlled play, gradual conditioning, and plenty of rest for puppies.
- Expect “fill out” to continue after height stops. Many dogs broaden in the chest, gain muscle, and develop a more adult head/neck look after they’ve mostly stopped getting taller. This is one reason owners feel like their dog is “still growing” even if height hasn’t changed.
- Re-check portions after spay/neuter or reduced activity. Metabolism and appetite can shift. If your dog’s height has plateaued but the scale keeps climbing quickly, it’s a good time to review calories and treats.
“I have GSPs. They tend to stop skeletal growth around 18-24 months, but they don’t fully mature (muscle developmental) until 3-4 years of age. Each breed is different, but Medium/large dogs take a while.”
r/DogAdvice
What to Avoid
- Don’t assume “bigger is healthier.” We’ve seen owners interpret extra weight as growth, when it may be excess body fat. Especially in growing dogs, staying lean is often easier on joints.
- Don’t switch off puppy nutrition too early (or too late) without a plan. The right timing depends on adult size and body condition. If you’re unsure, your vet can help you choose an appropriate transition window.
- Don’t compare your dog too literally to a friend’s dog. Even within the same breed, lines mature differently, and mixes can be especially variable. Use trends in your dog’s measurements and body condition instead of someone else’s timeline.
- Don’t push intense impact exercise while your dog is still growing. If you suspect your dog’s growth plates are still open, we’d avoid making them a weekend warrior with repetitive hard landings (for example, nonstop high jumping for long sessions).
- Don’t chase a “predicted adult weight” as a target. Estimates — especially shelter guesses — can be wrong. Your goal is a healthy body condition and steady development, not hitting a specific number on the scale.
- Don’t ignore persistent lankiness plus low energy or poor appetite. Awkward adolescent proportions can be normal, but poor overall thriving isn’t something to chalk up to “just growing.” It’s worth a vet conversation.
“Our shelter estimated ours would be 50-60 pounds, but he stopped growing at less than 30 pounds – he’s a little nugget and is the perfect size! Smaller dogs stop growing earlier, I think ours was done around 6 months or so.”
r/DogAdvice
When to Consult a vet
- Your dog’s growth seems stalled very early (for example, a young puppy not gaining appropriately) or your dog seems to be losing weight while “still growing.”
- Rapid weight gain after height has plateaued, especially if your dog is becoming noticeably rounder or less active — this can shift stress onto joints.
- Limping, stiffness, or repeated soreness during adolescence; growing dogs can be prone to orthopedic issues that benefit from early evaluation.
- Digestive issues that interfere with growth, such as chronic diarrhea, frequent vomiting, or poor appetite — nutrient absorption matters for healthy development.
- You need guidance on diet timing for a large or giant breed, including when to transition to adult food and how to keep growth steady rather than too fast.
- You’re planning high-impact training or sports and want a realistic view of whether your dog is likely done with skeletal growth.
FAQ
How can you tell if your dog is done growing?
In many dogs, the clearest clue is that height stops changing for several weeks to months, while appetite and energy stabilize. You may still see “filling out” afterward — more muscle, a deeper chest, and a more adult outline. If it’s important to know whether skeletal growth is finished, a vet can discuss whether growth plate status should be evaluated.
When do small dogs stop growing compared to large dogs?
Small dogs often reach adult height earlier in the first year, while large and giant breeds commonly take longer — often closer to the second year for skeletal maturity. That difference is one reason large-breed adolescents can look gangly for longer. AKC resources frequently emphasize that size and breed type change the timeline significantly.
Is a dog still “growing” if they’re gaining weight after their height stops?
Sometimes, yes: weight gain can reflect normal maturation, including increased muscle and adult body shape. But weight gain can also be excess body fat, especially if calories and treats stay high after the growth spurt ends. We’d use body condition (waist, rib feel, overall shape) and your vet’s guidance to tell the difference.
Do mixed-breed dogs stop growing at predictable ages?
Mixed breeds can be harder to predict because adult size and maturation rate depend on the genetic mix. Many still follow the general rule that smaller adult size tends to finish earlier and larger adult size tends to finish later, but the “end point” can be blurry. If you’re uncertain, your vet can help interpret your dog’s growth curve and body condition over time.
Does spaying or neutering change when dogs stop growing?
It can affect growth patterns because sex hormones play a role in growth plate closure and body composition. The best timing is individualized and is worth discussing with your vet, especially for large breeds where joint development is a common concern. For a research-grounded overview, we’d look to AVMA-aligned educational materials and peer-reviewed veterinary journals when weighing risks and benefits for your specific dog.
Bottom Line
Dogs typically stop getting taller sometime between 6 and 24 months, with smaller dogs finishing earlier and larger/giant breeds taking longer; many then continue to “fill out” with muscle and adult proportions. If your dog’s height has plateaued but their body is still changing, that can be normal maturation — but sudden shifts, pain, or poor growth are good reasons to loop in a vet. We’d stick with size-appropriate nutrition, steady tracking, and vet check-ins when something feels off, and revisit if new research shifts the consensus.