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.

Stages of Puppy Growth

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 and there is no “one size fits all” puppy growth chart. The majority of breeds will become 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. Puppies will experience the fastest growth rate 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 it takes time for puppies to mature and start behaving like adults. For example, Border Collies and other herding dogs don’t mature and stop behaving like puppies until they reach about 2 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, but this guide can help your furbaby kick that habit for good! When they stop their immature, hyperactive, or destructive behavior, it’s a safe bet that adulthood isn’t too far off.

It’s important to feed your pup the appropriate type and quantity of food during each stage of their life, this handy guide can help. If your four-legged child isn’t as enthusiastic about food as you’d like, you can add these food toppers to entice them to eat up.

Small Breeds

Small breed puppies tend to reach their full-sized framework between six and eight months old, and they'll typically fill out to their healthy average weight by 12 months old.

Small breeds include:

• Pugs
• Chihuahuas
• Boston Terriers

Medium Breeds

Medium breeds typically reach their full-sized framework between 12- 15 months old, but they usually won't reach their full weight until they're closer to 18 months old.

Medium breeds include:

• Border Collies
• Standard poodles
• Pit Bulls

Large Breeds

The larger the breed, the slower their growing process. Most large puppies won't reach their full-sized frame until 15-18 months old and won’t fill out into their full adult weight until they're about two years old.

Large breeds include:

• German Shepherds
• Weimaraners
• Labradors

Giant Breeds

These big babies 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.

Large breeds include:

• Saint Bernards
• Newfoundlands
• Mastiffs