Boston Terrier Size Guide How Big Does a Boston Terrier Get - Puppy Weight Calculator

In this Boston Terrier size guide, we’ll be covering all about the size and growth patterns of Boston Terriers from birth to adulthood. Additionally, we’ve created an interactive Boston Terrier size chart and weight calculator so you can predict and track your puppy’s size. Let’s dive in!

Boston Terrier
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Our handy interactive puppy growth chart and calculator takes all the hard work out of predicting your puppy’s potential adult size. This helps you to know exactly what you are in for.

Psst! Check Out These Awesome Puppy Things!

Boston Terrier Size Predictions: How Big Do Boston Terriers Get?

The Boston Terrier is one of the most popular dog breeds in American households. They’re small yet sturdy little pups who are well-known for their affectionate and gentle nature. If you’re looking for a playful dog who can live well in an apartment, the Boston Terrier might just be the right choice for you. They’re also great with children, which makes the Boston Terrier the perfect family dog. 

So how big do Boston Terriers get? By the American Kennel Club breed standards, the Boston Terrier’s size should fit within 12 to 25 pounds in weight and 15 to 17 inches in height. Of course, some pups might run slightly smaller or larger, depending on a variety of factors. These include their gender, the size of their parents, their diet, and how much they exercise. 

As puppies go through extremely fast growth spurts, it’s especially important your furry little companion gets the correct nutrition and nourishment it needs to grow into a healthy adult. Most importantly, make sure you feed your puppy the correct amount of food, and opt for specially formulated food for small breed puppies. 

Boston Terrier
Photo by Erik Mclean on Unsplash

Are There Different Sizes Of Boston Terriers?

Boston Terriers are in fact categorized in three weight classes. The smallest weight class includes dogs who weigh less than 15 pounds. Then there’s a weight class for pups who weigh more than 15 pounds and less than 20 pounds. Lastly, the largest weight class represents Boston Terriers weighing between 20 and 25 pounds. 

Based on that, we can say that the Miniature Boston Terrier size could correlate to the 15 to 20 pound weight class. The Boston Terrier’s toy size would then apply to the smallest weight class. However, more often than not, breeders promoting Teacup, Toy, or Mini Boston Terriers are most likely using unethical practices to breed super tiny Boston Terriers from runts or puppies with the dwarfism gene. Although they are just as cute and amazing, dogs who are bred too small are at a much higher risk of developing health problems and chronic diseases. 

Boston Terrier
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If you’ve decided to adopt your new family member from a breeder, they will be able to let you know about the average size of puppies and full-grown Boston Terriers in the litters. Some breeders specialize in just one of the three weight categories, some have a wider selection. Above all, do your research and don’t fall for breeders who advertise the Teacup Boston Terrier size, as we don’t recommend supporting unethical breeding practices.  

Additionally, just like most other dog breeds, there can be a small difference between female and male Boston Terriers. Male pups can be a little bit heavier and taller than females. The difference is usually around an inch in height and a few pounds in weight. 

Boston Terrier Size Charts & Growth Patterns – Month Wise 

Although it’s difficult to exactly predict when a dog will finish growing or how big they will be once fully-grown, all dogs follow very similar growth patterns. Typically, we can expect puppies to do most of their growing in the first 6 months. Then, their growth will start to slow down, until it plateaus at their adult weight around 12 months old. 

Additionally, this is why it’s particularly important that your Boston Terrier puppy gets the correct nourishment he needs to grow that adorable little body into a healthy adult one. Check out these guides on best dog food for puppies here.

Let’s have a look at the average Boston Terrier size predictions by age:

Age3 months6 months9 months12-14 months
Weight6.5 pounds14 pounds20 pounds23 pounds
Height9 inches12 inches15 inches16 inches

*Keep in mind that a dog’s height is measured from their withers, that’s the highest part of their shoulder blades

As we can see from the Boston Terrier size chart above, at 6 months old they’ve already reached slightly more than half of their adult weight and most of their full height. At 9 months old, a larger Boston Terrier will reach almost all of their full height, but will still be gaining a few more pounds and fill out over the upcoming months. 

Boston Terriers tend to finish growing around their first birthday or a few months after that. We can expect smaller Boston Terriers to reach their full-grown size sooner – some Boston Terriers will reach their adult size as early as 10 months old. Larger pups will most likely take up to 14 months to finish growing. 

If you’d like to predict your Boston Terrier’s full-grown size, and track their growth from puppy to adult, make sure to check out our interactive Boston Terrier size chart and puppy weight calculator. Just enter your puppy’s details and you’re good to go! 

Is A Boston Terrier A Small Or Medium Dog?

Even though Boston Terriers have a distinctive sturdy, muscular build, they are in fact a small-sized breed. Thanks to their small size and great personality, Boston Terriers are perfect for apartment living.  

How Big Do Boston Terriers Grow?

Boston Terriers weigh around 12 to 25 pounds and stand at 15 to 17 inches tall at the shoulder. The average Boston Terrier’s size is then divided into three weight categories: less than 15 pounds, 15 to 20 pounds, 20 to 25 pounds. If you’re adopting your puppy from a breeder, you can ask them about the sizes of the parents, and how big the puppies usually turn out to be. Typically, the litters should be pretty consistent in terms of how big the puppies are.  

At What Age Is A Boston Terrier Full Grown?

Depending on their size, we can expect Boston Terriers to finish growing anywhere around 10 to 14 months. A smaller Boston Terrier will most likely finish growing around 10 to 12 months old. A larger pup can take up to 14 months to reach their full-grown size.  

Boston Terrier
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You can calculate their potential adult weight at 23 weeks by taking what they weigh at that age and multiplying it by two.

A different formula you could use is:

  1. Growth = current weight / current age in weeks
  2. Adult weight = Growth x 52 (number of weeks in one year)

So, for example, if your 12-week old pup weighs 18 pounds. You simply divide the current weight by their age in weeks and multiply the result with 52:

18/ 12 = 1.5
1.5 x 52= 78 pounds

78 pounds would be the expected weight of your adult-sized Boston Terrier.

Hopefully, our Boston Terrier size guide has been a helpful resource in helping you understand the size and growth patterns of this gorgeous little pal. Above all, knowing what to expect is crucial when you want to provide your pup the absolute best throughout all their life stages. 

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