Puppy Growth Chart & Stages: How to Tell When a Puppy Is Fully Grown

There’s nothing quite like the excitement of bringing a new puppy into your home. After you’ve prepared for their arrival, you can enjoy watching them grow and develop into adult dogs! When you adopt a puppy, you’re never quite sure how big they will grow into their adult size, especially if you adopt a mixed breed. However, one thing never changes – the need for a nutritious and well-balanced diet.

Puppy Growth Stages

While many people believe that a puppy stops growing by the time they are one year old, this simply isn’t the case across the board. Stages of puppy growth vary by breed – there is no “one size fits all” puppy growth chart. The majority of breeds will be fully grown between 12-18 months, although the largest breeds can take longer. This is because larger breeds require a bit more time for their bones and joints to fully develop. Healthy growth is the result of many things, like training, exercise, and of course, a healthy diet comprised of high quality natural dog food.

It’s important to feed your pup the appropriate type and quantity of food during each stage of their life – our handy Puppy Feeding Guidelines can help. A quality, natural dog food can help your pup grow up to be healthy, happy, and strong! If your four-legged child isn’t as enthusiastic about food as you’d like, you could try adding one of our food toppers as an enticing incentive to encourage your pal to eat up.

Puppies will experience the fastest growth in their first six months, and most puppies will have reached 60% of their adult height by the time they are four months old. They experience skeletal growth first, and when this stage is complete, your dog will stop getting bigger. Then, your pup will fill out and continue to develop muscle and fat over time – just like humans!

Keep in mind that puppy growth involves both their minds and their bodies, and they don’t necessarily happen at the same rate. It takes time for puppies to mature and start behaving like adults, even if they appear fully grown. For example, Border Collies and other herding dogs don’t typically mature and stop behaving like puppies until they reach the age of about two years old.

A good way to determine when your puppy has become an adult is to pay attention to their behavior. One of the worst growing pains of raising a puppy is the biting stage, which could have you growling in frustration. If that’s the case, consult our Puppy Training Guide for helpful advice on how to teach your fur baby to kick that habit for good! If your pet happens to stop their immature, hyperactive, or destructive behavior on their own, it’s a safe bet that adulthood isn’t too far off.

Small Breeds

Small breed puppies, known for their rapid growth, typically reach their full-grown size between six and eight months old. During this crucial growth phase, it's important to provide them with the best dog food for small dogs, designed to meet their unique nutritional needs.

By the time they reach 12 months old, these puppies usually fill out to their healthy average weight, having benefitted from a diet tailored to support their development.

Small breeds include:

• Pugs
• Chihuahuas
• Boston Terriers

Medium-sized Breeds

Medium breeds, with their distinct growth patterns, usually reach their full-grown size between 12-15 months old. During this period, providing them with the best dog food for medium dogs is crucial to support their development. While they attain their full height in this timeframe, they typically won't reach their full weight until they're closer to 18 months old.

Medium-sized breeds include:

• Border Collies
• Standard poodles
• Pit Bulls

Large Breeds

Generally, the larger the breed, the slower their growing process. During this extended growth phase, feeding them puppy food that's formulated for large breeds is essential to support their development and ensure proper bone health. Most large puppies won't reach their full-sized frame until 15-18 months old and won’t fill out their full adult weight until they're about two years old.

Large breeds include:

• German Shepherds
• Weimaraners
• Labradors

Giant Breeds

These giant-sized pups take the longest to reach full size. Their basic framework is in place by about 18 months old, but it can take until age two or three for them to reach their heavy full weight and muscle mass. As you may have guessed, it’s essential to provide your pup with a healthy, natural dog food to ensure they receive the proper amount of nutrients – especially these big babies!

Giant breeds include:

• Saint Bernards
• Newfoundlands
• Mastiffs

When Is a Puppy Fully Grown?

You can tell when a puppy is fully grown based on the breed.

Puppy Growth Milestones

There are some other key milestones in puppy growth:

• 4 months: Most puppies reach 60% of their adult height
• 6 months: Small breeds typically reach full-grown size
• 12-18 months: Most breeds reach full-grown size, with larger breeds taking longer
• 1-2 years: Puppies fill out and develop muscle and fat, reaching their full adult weight

(And don't forget about puppy teething! It's one milestone you're not soon to forget.)

How Nutrition Affects Puppy Growth

Your puppy's growth and development depend on more than just time, they also rely on proper nutrition. Our premium puppy food is made with high-quality ingredients, protein, vitamins, and minerals to support healthy bones, muscles, brain development, and immune function throughout every stage of puppyhood. So, if you're raising a small, medium, or large breed, you'll find complete and balanced recipes designed to help your puppy thrive. Shop our puppy food collection today and give your growing companion the nutrition they deserve.

Healthy Growth Starts With the Right Nutrition

It's important to remember that the journey to adulthood varies greatly among breeds. How long a dog takes to reach full size, and how fast puppies grow, are questions with breed-specific answers. Remember: If you have specific questions or concerns regarding your pet’s growth and health, make sure to consult your vet. And hey, whether you're raising a tiny Chihuahua or a majestic Mastiff, take our quiz and find out the right natural dog food tailored to your furry friend’s specific needs – and the key to nurturing a healthy, happy adult dog.

Frequently Asked Questions

• Q - How long do puppies grow?

• A - The length of time a puppy grows depends on their breed and size. Small breeds often reach their full size between 6 - 12 months, while medium breeds typically finish growing around 12 - 18 months. Large and giant breeds can continue growing until they are 18 - 24 months old, with some giant breeds taking up to three years to reach their full weight and muscle mass.

• Q - When do puppies stop growing?

• A - When puppies stop growing depends largely on their breed and size. Small breeds often reach their full size between 6- 12 months, while medium breeds typically stop growing around 12 - 15 months. Large breeds may continue growing until 18 months, and giant breeds can take 2 - 3 years to fully mature. Although many puppies reach their adult height before they're fully grown, they may continue developing muscle and filling out as they transition into adulthood. Feeding a complete and balanced puppy food throughout each stage of growth helps support healthy development.

• Q - How can I tell how big my puppy will get?

• A - Your puppy's adult size is influenced by genetics, breed, age, and current weight. Looking at the size of their parents, breed mix, and growth rate can provide helpful clues. If you're unsure, your veterinarian can offer a more accurate estimate based on your puppy's development.

• Q - What should I feed a puppy?

• A - Growing puppies need a complete and balanced diet that provides high-quality protein, healthy fats, vitamins, and minerals to support healthy bones, muscles, brain development, and immune function. Choosing a high-quality puppy food formulated specifically for growing dogs helps ensure they receive the essential nutrients they need during this important stage of life.

• Q - How often should I feed my puppy?

• A - Young puppies generally need three to four meals per day to support their rapid growth and high energy levels. Puppy feeding frequency will gradually change as your dog grows, with most puppies transitioning to two meals per day as they get older. Always follow the feeding guidelines on your puppy food and adjust portions based on your puppy's age, size, and activity level.

Updated July 14, 2026