When Is a Labrador Retriever Fully Grown?
A Labrador Retriever is typically fully grown by 18 to 24 months, but different parts of their body mature at different times. Most Labs reach their full height by around 12 months, while their muscle mass and chest continue to fill out well into their second year. Mentally and emotionally, they may take even longer to mature — often not settling into a calmer temperament until 2 to 3 years of age.
Growth Timeline of a Labrador Retriever
Understanding when a Lab is considered “fully grown” depends on what aspect you’re referring to — height, weight, muscle development, or behavior. Here’s how their growth typically unfolds:
0–6 Months: Rapid Puppy Growth
The first few months with a Labrador puppy bring big changes — fast. By six months, they often triple their size, growing so quickly that their legs can look a bit too long for their bodies. It’s a clumsy stage where they’re all paws and energy. During this stage, they may begin teething and chewing everything in sight.
🦴 Tip: This is the stage where proper nutrition and controlled exercise matter most. Overfeeding can lead to obesity and orthopedic issues like hip dysplasia (see OFA).
6–12 Months: Slower Height Gains
By the one-year mark, most Labs have reached 80–90% of their adult height. They may look lean and leggy, and while they seem physically strong, their bones and joints are still developing.
⚠️ Note: Avoid high-impact activities like jumping from heights or running on hard surfaces. The American Kennel Club (AKC) advises letting joints mature to prevent long-term damage (source).
12–24 Months: Filling Out Phase
From one year to two years, your dog will continue to gain muscle mass, broaden in the chest, and become more proportional. This is when they start looking like the stocky, athletic adults the breed is known for.
💡 Why it matters: Neutering too early (before 12 months) can sometimes delay or alter physical development. Discuss timing with your vet based on your dog’s individual growth pattern.
Emotional and Mental Maturity
Even though a Labrador may look fully grown by their first birthday, they often remain puppylike in behavior until two or even three years old. They’re known for their playful, energetic temperament, which can make them seem immature longer than other breeds.
🧠 Training becomes more effective as they mature mentally. Most of them respond best to positive reinforcement and consistent routines once they’ve reached that emotional turning point — usually around 2.5 years.
How Big Do Labrador Retrievers Get?
They are a medium to large breed. Here’s what you can expect once they’re fully grown:
| Gender | Height (at shoulder) | Weight Range |
|---|---|---|
| Males | 22.5 to 24.5 inches | 65 to 80 pounds |
| Females | 21.5 to 23.5 inches | 55 to 70 pounds |
🧬 Genetics, diet, and lifestyle all play a role in where your dog falls within these ranges.
Factors That Affect Growth in Labs
Growth can vary slightly from one Labrador to another. Several factors influence how quickly and how fully they mature:
Genetics: Bloodlines matter. Working-line Labs tend to be leaner and more energetic, while show-line Labs are usually bulkier.
Nutrition: A well-balanced, breed-appropriate diet supports steady growth. Avoid excessive calcium or protein, which can contribute to skeletal issues.
Exercise: Controlled activity is vital. Overexercising too early can damage growing joints.
Spaying/Neutering Timing: Hormonal changes can influence growth plates and behavior. Studies suggest waiting until at least 12–18 months in large breeds.
Signs Your Labrador Is Fully Grown
Noticing subtle physical and behavioral changes can help you determine if your Lab is fully grown:
✅ Muscle tone is filled out and evenly distributed
✅ Chest appears broader and deeper
✅ Energy levels stabilize (less hyperactive zoomies)
✅ Shows better impulse control during training
✅ Appetite is more regulated
What to Expect As Your Lab Matures
Nutrition
Once your Lab’s growth starts to taper off — usually around 12 to 18 months — it’s time to move to an adult dog food. Choose formulas that include glucosamine and chondroitin to help keep their joints strong and healthy.
🛒 Recommended: Hill’s Science Diet Large Breed Adult — formulated specifically for large breeds.
Exercise
Adult Labs need about 60 minutes of exercise daily, including fetch, swimming, or long walks. Mental stimulation is just as important — puzzle toys and obedience training go a long way.
Health Checkups
Schedule regular wellness exams. Vets will monitor:
Growth plate closure
Joint health
Weight management
Dental health
Frequently Asked Question(s)
Do male and female Labs grow at different rates?
Yes, male typically grow larger and sometimes take slightly longer to fill out compared to females.
Is my Labrador overweight or still growing?
Feel your dog’s ribs — they should be easily felt but not visible. If unsure, consult your vet. Growth slows significantly after 12 months, so most weight gain after that should be muscle, not fat.
When do Labs calm down?
They begin to mellow out between 2 to 3 years of age, although daily exercise is key to managing energy at any stage.