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Westie Size: Weight Chart, Growth Chart & More

Westies are small dogs. Fully-grown Westies measure between 10–11 inches (25–28 centimeters) in height and weigh between 15–20 pounds (7–9 kilograms). When they reach their physical maturity, their neck size measures between 14–16 inches (35–centimeters) in circumference.

Many dog owners prefer small breeds because they are easy to maintain. They are also cute.

Westies are one of these small, cute, lovable dogs. But how big do they get and how fast do they grow?

This article explores all the aspects of Westies’ size:

  • Height
  • Weight
  • Growth stages
  • Factors that influence their size

You will also learn how big they are compared to other breeds.

How Big Do Westies Get?

Westies weigh between 15 and 20 pounds (7 and 9 kilograms) and measure between 10 and 11 inches (25 and 28 centimeters) at shoulder length. When they reach their physical maturity, their neck size is between 14 and 16 inches (35 and 40 centimeters).

This table lists the measurements of a fully grown West Highland White Terrier.

Height10–11 in (25–28 cm)
Weight15–20 lbs (7–9 kg)
Neck size14–16 inches (35–40 cm)
How Big Do Westies Get

Is a Westie a Small or Medium Dog?

West Highland White Terriers are small dogs. Breeds that weigh less than 22 pounds are considered small-sized, and westies weigh between 15 to 20 pounds. 

Their bodies are compact and well-balanced. Westies have a longer height than the distance from the root of their tail to the wither.

3 Factors That Affect Westies’ Size

West Highland White Terriers size is determined by genes and influenced by other factors such as exercise, nutrition, and health.

1. Exercise

Propper amounts of exercise allow Westies to keep a healthy weight. It also keeps their hormones in check, which ensures balanced growth.

The amount of exercise they need depends on their age. 

Keep their purpose in mind. Westies were bred for vermin control, meaning they are used to moving a lot.

2. Nutrition

Westies Nutrition

Nutrition is a key factor in the way Westies develop. If they are not provided with the right amount of nutrients, they can experience hormonal changes which affect their growth. 

Westies who lack key nutrients from their diet can experience low bone density. This results in underdevelopment and growth delay.

3. Health Issues

Westies Health Issues

There are two main health issues that influence the growth of Westies: Acromegaly and Pituitary Dwarfism. 

Westies with Agromegaly produce higher amounts of growth hormone than normal[1]. As a result, they are considerably larger.

Pituitary Dwarfism cause Westies to make low months of growth hormones, which leaves them smaller than their regular size.[2]

Westies can also suffer from other growth disorders that can affect their size:

  • Bowed legs
  • Abnormal posture
  • Hip dysplasia
  • Difficulty walking
  • Muscle wasting
  • Joint pain

How Much Do Westies Weigh?

Westies weigh between 15 and 20 pounds (7 and 9 kilograms). They weigh around 0.35 pounds at birth. By the time they are three months old, Westies weigh 8.2 pounds (3.7 kilograms), on average. Six months old puppies weigh around 14.8 pounds (6.7 kilograms). Male Westies are heavier than females.

Male Westie Weight

Male Westies weigh 17 to 20 pounds (8 to 9 kilograms). Because of their hormones, they grow larger than females. 

Female Westie Weight

Female Westies weigh 15 to 18 pounds (7 to 8 kilograms). They are smaller than males and reach their physical maturity earlier. 

Female Westie Weight

Westie Weight Chart

Westies grow faster during the first six months. Between the age of 3 and 6 months, they gain around 2 pounds (1 kilogram) per month. Between 6 months and 12 months, their growth rate starts to decrease until it gets to 0.2 pounds (0.1 kilograms) per month.

This table illustrates Westies’ weight by age.

Age Average Weight in PoundsAverage Weight in Kilograms
3 months8.2 lbs 3.7 kg
4 months11.0 lbs 5.0 kg
5 months13.2 lbs 6.0 kg
6 months14.8 lbs 6.7 kg
7 months16.3 lbs 7.4 kg
8 months17.2 lbs 7.8 kg
9 months17.9 lbs 8.1 kg
10 months18.3 lbs 8.3 kg
11 months18.5 lbs 8.4 kg
12 months18.7 lbs 8.5 kg

When Are West Highland White Terriers Fully Grown?

Westies are fully grown by the time they reach 12 months. At this point, they measure between 7 and 11 inches (25 and 28 centimeters) in height and weigh between 15 and 20 pounds (7 and 9 kilograms).

Small breeds reach their full size faster than medium or large breeds. Airedale Terriers, the largest Terrier breed, stop growing between 12 and 15 months. By comparison, Westies develop relatively quickly, as at 12 months of age they are fully matured.

Even though they stop growing after 12 months, not all Westies reach their emotional maturity at this point. Some still act like teenagers even if they look like adults.

This table describes the six growth stages of Westies.

Westie Growth Stage PeriodDescription
Neonatal stage0–2 weeksWestie puppies lack teeth, and can’t hear or see.
Transitional stage2–4 weeksWestie puppies begin to open their eyes and their ear canals. They begin exploring the space around them.
Socialization stage4–12 weeksWestie puppies’ sense of smell and ability to hear fully develop. They are able to run, stand, or play. 
Juvenile stage10–16 weeksWestie puppies’ teeth are fully grown.
Early adolescence4–6 monthsWestie puppies start experiencing sexual drive. 
Adolescence6–12 monthsWesties reach their sexual maturity. 

Does Neutering Affect Westies’ Size?

No, neutering or spaying Westies does not influence their size or growth rate.[3]

The common belief that neutered dogs are smaller is not backed by science. This medical procedure has been performed for a long time but there is no evidence so far that sterilization causes a slower growth rate. 

West Highland White Terrier Size Comparison

Westies are average-sized compared to other Terriers. They are smaller than Airedale Terriers, the largest terrier breed. Compared to other popular breeds, West Highland White Terriers are relatively small. They are half the size of Labrador Retrievers and almost double the size of Chihuahuas.

West Highland White Terrier Size Comparison

Westie Size vs. Popular Breeds

This table illustrates the size of Westies compared to other popular breeds.

BreedHeight in InchesWeight in poundsHeight in CentimetersWeight in Kilograms
Westie10–11 15–20 25–287–9 
Beagle13 -15 20–30 33–389–14 
German Shorthaired Pointer21–25 45–7053–63.520 –32 
Labrador Retriever[4]21.5–24.5 55–70 55–6225–32
French Bulldog12 16–28 30.5 7–13
Golden Retriever[5]21.5–24 55–75 55–6125–34
German Shepherd[6]22–26 55–90 56–6625–41
Bulldog[7]14–15 40–50 36–38 18–23
Cavalier Spaniel12–1313–1830–336–8
Rottweiler22–24 80–13556–63.536 –61
Poodle (Standard)>15 40–70 >3818–32
Dachshund (Standard)8–9 16–32 20–237–14.5

Westie Size vs. Smallest and Largest Dog Breeds

Westies weight is the equivalent of 10% of English Mastiffs (the largest breed in the world) weight. Compared to Chihuahuas (the smallest breed in the world), Westies measure almost double in size.

This table compares the size of Westies to the largest and smallest dog breeds.

BreedHeight in InchesWeight in PoundsHeight in CentimetersWeight in Kilograms
Westie10–11 15–20 25–287–9 
English Mastiff27–35200–23069–9091–104

Westie Size vs. Other Terriers

The size of Terriers varies among breeds. Their weight varies from 7 to 70 pounds. Westies are relatively small considering this range. They are larger than Yorkshire Terriers but considerably smaller than the largest terrier breed, the Airedale Terrier.  

This table compares the size of West Highland White Terriers to other Terrier breeds.

BreedHeight in InchesWeight in PoundsHeight in CentimetersWeight in Kilograms
Westie10–11 15–20 25–287–9 
Airedale Terrier20–23 50–7051–5823–32
Boston Terrier9–17 8–25 38–434.5–11
Jack Russell Terrier20–23 50–7051–5823–32


Westies are between 10 and 11 inches (25 and 28 centimeters) tall and weigh between 15 and 20 pounds (7 and 9 kilograms). They are small-sized dogs that reach their physical maturity when they are 12 months old. Female Westies are a bit smaller than males. The factors that influence their size are genetics, nutrient intake, physical exercise, and health issues.

About Ioana Moldovan

Ioana is a Misfit Animals staff writer and psychology student interested in animal behavior. She likes to dive deep into the newest scientific studies to find out the latest discoveries in the field.

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