When Do Boston Terriers Stop Growing

Raising a Boston Terrier from a puppy has been a very rewarding experience for our family. We’ve been able to see our dog go through all the growth stages and be part of her socialization. 

Boston Terriers typically stop growing between 12 and 14 months, depending on their size. Smaller dogs may stop growing earlier than this. They will reach a maximum weight between 12 and 25 pounds and stand 15 to 17 inches tall. 

If you are curious about when your Boston Terrier will stop growing or what occurs during the different growth stages, continue reading. We’re also going to cover information on the different sizes of Boston Terriers and other information about their growth.

When Do Boston Terriers Stop Growing?

Your Boston Terrier will finish growing at approximately 12 to 14 months. The actual timing is dependent on how large your dog is going to grow. If you purchased your dog from a reputable breeder, they should be able to give you an approximate size.

The breeder will base this estimate on their family tree and how their family members filled out. A benefit of purebred dogs is the consistency of their size.

How Big Will Your Boston Terrier Grow?

According to AKC breed standards, a Boston Terrier should weigh between 12 and 25 pounds and stand 15 to 17 inches in height. Some dogs may run smaller or larger, depending on various factors.

Your Boston Terrier’s gender, diet, level of exercise, and parents’ sizes can all affect their final weight and height. Because puppies go through extremely fast growth spurts, you will need to ensure that you are providing adequate nutrition and nourishment.

image of a ruler for When Do Boston Terriers Stop Growing post

Do Boston Terriers Come in Different Sizes?

Boston Terriers are known to have three different weight groups:

  • Under 15 pounds
  • Greater than 15 pounds but less than 20 pounds
  • Greater than 20 pounds but less than 25 pounds

Based on this information, you can place miniature Boston Terriers into the second group and teacup Boston Terriers into the smallest group. 

Do Boston Terriers Reach Half Their Size at a Particular Age?

At around 14 to 16 weeks of age, your Boston Terrier will be roughly half the size of what they will grow to be. While this is not a perfect science, you will have a general idea of how big your dog is going to grow.

You can also judge what size your Boston Terrier will be by the amount of loose skin they have. When they reach their full size, they won’t have a lot of loose skin so what they have now, they will grow into.

If you see a lot of loose skin now, you’re in for some more growth spurts in the near future. 

The Growth Stages of Boston Terriers

Your Boston Terrier is considered to be a small breed and will reach maturity faster than a larger breed like a German Shepherd. 

While growing from a puppy to an adult, your dog will go through changes, including physical developments, emotional developments, and growth and weight gain. There are also five puppy growth stages your Boston Terrier will experience.

The Neonatal Stage (Birth to 2 Weeks)

While puppies are in the neonatal stage, they cannot see or hear and have no teeth. However, they immediately have senses of touch and taste following their birth. They require warmth and will spend most of their time nursing or sleeping.

Their mother will have the most influence over them at this stage. She will be their only source of food and warmth. 

The Transitional Stage (2 to 4 Weeks)

During the transitional stage, Boston Terrier puppies will develop their senses of smell and hearing. Their eyes will open and teeth will begin appearing. 

At this stage, they will also start to move around, learning how to stand, take their first steps, wag their tails, and bark. By the 4th or 5th week, their eyesight will fully develop.

The Socialization Stage (3 to 12 Weeks)

The socialization stage is a period of rapid development. During this stage Boston Terrier puppies will gain control over their bladders and bowel movements, learning to move away from their bedding before eliminating. 

They’ll also begin playing more as they become aware of their surroundings. Through interactions with each other and the humans around them, they become socialized, learning how to be a dog and how to interact with people.

During this time, they’ll begin to get their vaccinations. Puppies will have gained full use of their senses and begin to experience real fear when interacting with everyday objects, requiring emotional support. They can also start learning basic commands toward the end of this stage. 

They need to be given as much experience as possible with other dogs, animals, people, and environments to improve their socialization. Additionally, they need to be given experience with being left alone to understand that this is acceptable.

How you handle your dog’s development during this stage will affect their behavior for the rest of their life. They will learn the proper way to interact with other animals and the right way to greet people other than their family. 

Boston Terriers Jojo and Bosco

The Ranking Stage (3 to 6 Months)

During this stage, your puppy’s adult teeth will start coming in, causing them to chew. You will need to provide a lot of positive reinforcement and spend a significant amount of quality time with your pup. Key activities will be training sessions, playtime, and exercise.

The Adolescence Stage (6 to 18 Months)

During this stage, your puppy will reach sexual maturity. They will also reach adulthood, setting into a grown-up personality and completing their growth. 

When Will a Boston Terrier Be Fully Grown?

Boston Terriers will finish growing between 12 and 14 months, depending on their size. However, smaller dogs can be completely grown by 10 to 12 months. Larger dogs, on the other hand, will take up to 14 months to completely finish growing. 


Boston Terriers are amazing, small dogs that grow quickly when compared to larger breeds. They reach half their size at approximately 14 to 16 weeks of age.

Your Boston Terrier will continue growing until they are approximately 12 to 14 months old. This is largely dependent on the final size of your dog and a smaller Boston Terrier can actually finish growing at 10 to 12 months. 

During the different stages of development, you will need to provide the support and positive reinforcement training that your dog requires. This way, you will ensure your Boston Terrier grows up to be a well-rounded, fully-adapted dog that interacts well with others.

Recent Posts