Boston Terrier Size & Weight Chart: How Big Do They Get?
Written for general planning, not medical advice — no one at Argos Paws is a veterinarian. If something is wrong with your dog right now, call your vet or the nearest emergency clinic.
Quick answer: A full-grown Boston Terrier typically weighs 10-25 lb (4.5-11 kg) and stands 15-17 in (38-43 cm) tall at the shoulder. Most reach their adult size by around 9-10 months.
Photo: Andreas Schlaugat · CC BY 3.0 · via Wikimedia Commons
Boston Terriers are a compact, tuxedo-marked breed nicknamed the "American Gentleman" for their dapper look and friendly, easygoing temperament. They are a popular choice for apartment living.
History and origin
The Boston Terrier holds the distinction of being one of the few dog breeds genuinely native to the United States. The breed originated in Boston, Massachusetts, in the 1870s, from a cross between a Bulldog and the now-extinct White English Terrier, producing a dog named "Judge" who is considered the foundation sire. Early Boston Terriers were considerably heavier and more pit-fighter in character; selective breeding over the following decades produced the refined, gentle companion seen today. The AKC recognised the breed in 1893, making it one of the first American breeds to gain recognition.
Temperament and personality
Boston Terriers manage to be enthusiastic without being exhausting — they are lively and playful in bursts but are equally content to sit quietly beside their person. They are people-oriented to the point of being described as "shadow dogs," following owners from room to room. Despite the "Terrier" in their name, they have very little of the tenacity or prey drive associated with working terrier breeds. They tend to get along well with children and other animals, and their expressive faces — raised eyebrows, wide eyes — make their moods unusually easy to read. They can be sensitive to tone of voice and tend to pick up on household stress.
Training and socialisation
Boston Terriers are among the more trainable small breeds: they are eager to please and respond well to consistent positive reinforcement. Keep sessions fun and short to hold their attention. Housetraining can take slightly longer than with some breeds, and a consistent schedule works better than corrections. One practical consideration for all brachycephalic breeds: avoid training or exercise in hot or humid conditions, and watch for signs of overheating (excessive panting, reluctance to continue). Recall and leash manners are straightforward to teach if started young.
| Size category | Small |
|---|---|
| Typical adult weight | 10-25 lb (4.5-11 kg) |
| Height at the shoulder | 15-17 in (38-43 cm) |
| Full grown by | 9-10 months |
| Life expectancy | 11-13 years |
The breed standard splits weight into three classes: under 15 lb, 15-20 lb, and 20-25 lb.
Boston Terrier weight chart by age (lb & kg)
Estimated weights for an average Boston Terrier puppy, based on the typical growth curve for a small breed. Males usually track toward the top of each figure, females toward the bottom.
| Age | Weight (lb) | Weight (kg) |
|---|---|---|
| 2 months | ~6 lb | ~2.7 kg |
| 3 months | ~10 lb | ~4.5 kg |
| 4 months | ~12 lb | ~5.4 kg |
| 5 months | ~14 lb | ~6.4 kg |
| 6 months | ~16 lb | ~7.3 kg |
| 9-10 months (full grown) | 10-25 lb | 4.5-11 kg |
When does a Boston Terrier stop growing?
As a small breed, Boston Terriers typically reach adult weight by around 9-10 months. Smaller breeds like the Boston Terrier reach full height and fill out fairly close together, so growth tends to look "done" all at once.
Use the Puppy Weight Predictor below — it's pre-loaded with the Boston Terrier's growth curve, so just enter your puppy's current weight and age.
Predict your Boston Terrier's adult weight
Enter your puppy's current weight and age to get an estimate based on this breed's typical growth curve.
Open the Puppy Weight PredictorHow much does it cost to feed a Boston Terrier?
A typical adult Boston Terrier (18 lb, average activity) needs roughly 530 kcal/day — about 0.3 lb (1.2 cups) of dry kibble per day, which works out to around $19/month at typical kibble prices. Fresh or subscription-style food usually costs more, around $212/month for the same dog. These are population-level estimates — use the calculator below for a number based on your dog's actual weight and food type, or see the Boston Terrier feeding chart for puppy amounts by month.
Estimate Boston Terrier food costs
Pre-filled with this breed's typical adult weight — adjust activity level and food type to get your monthly estimate.
Open the Dog Food Cost CalculatorBrowse dog food sized for a Boston Terrier
Compare dry, wet, and breed-specific formulas — filter by your dog's size and life stage to narrow it down.
Browse dog food on Amazon(affiliate link)How old is my Boston Terrier in human years?
The old "×7" rule doesn't hold up — small breeds like the Boston Terrier age at their own rate, not a generic one. Use the calculator below, pre-set to this breed's size.
Convert your Boston Terrier's age
Pre-filled with this breed's size category for a more accurate human-year estimate than a flat multiplier.
Open the Boston Terrier Age CalculatorCommon health considerations
- Brachycephalic airway syndrome can make heat tolerance and breathing during exercise a concern.
- Eye issues, including corneal ulcers, are relatively common given their prominent eyes.
- Patellar luxation and allergies/skin issues are also documented in the breed.
This is general breed-level information, not a diagnosis or a prediction for any individual dog. Talk to your vet about health screening and preventive care specific to your dog.
Is pet insurance worth it for a Boston Terrier?
See a typical monthly premium for this breed and whether it would likely pay off against a major vet bill.
Boston Terrier insurance costSimilar breeds
Based on energy level, living-space fit, and care needs, these breeds are closest to the Boston Terrier:
Take our breed match quiz
Answer a few quick questions about your lifestyle and living space to see which breeds — not just the Boston Terrier — actually fit best.
Take the Breed Match QuizFrequently asked questions
How much does a full-grown Boston Terrier weigh?
A full-grown Boston Terrier typically weighs 10-25 lb (4.5-11 kg), making it a small breed. Individual dogs vary within that range depending on sex, genetics, and body condition — use the Puppy Weight Predictor above for an estimate based on your specific puppy's current weight and age.
How tall is a full-grown Boston Terrier?
A full-grown Boston Terrier stands 15-17 in (38-43 cm) tall, measured at the shoulder (withers). The breed standard splits weight into three classes: under 15 lb, 15-20 lb, and 20-25 lb.
When does a Boston Terrier stop growing?
As a small breed, Boston Terriers typically reach adult weight by around 9-10 months. Height typically levels off a bit before this; smaller breeds like this one fill out relatively quickly once they reach height.
Is a Boston Terrier a good first dog?
Generally yes. The Boston Terrier is forgiving enough for most first-time owners, as long as you're realistic about its exercise and care needs going in rather than assuming any dog is "easy."
How much exercise does a Boston Terrier need?
A moderate, manageable amount — roughly 30-45 minutes a day covers most Boston Terriers, split across a couple of walks or a walk plus playtime.
Is a Boston Terrier good with kids?
Yes, the Boston Terrier is one of the more reliably kid-friendly breeds, generally patient and sturdy enough for boisterous play. Always supervise young kids with any dog regardless of breed reputation.
How much grooming does a Boston Terrier need?
About as wash-and-go as it gets. The Boston Terrier needs minimal brushing and rarely requires professional grooming.