The West Highland White Terrier is a popular choice for both families and individuals who want a small dog with a big personality.
But just how small are Westies? How big do Westies get?
Westies generally grow to be between 9 and 12 inches tall and weigh between 13 and 22 pounds, with males typically being larger than females.
For context, I grew up with a female Westie, and while I don’t remember her exact weight, she was small enough for a child to carry around. On the other hand, she was also big and strong enough to pull me around the block on my roller skates.
In this post, I will go over how quickly a Westie puppy grows, the size differences in male and female Westies including growth charts, and give some tips on assessing your Westie’s weight.
Westie Puppy Growth
How Much Do Westie Puppies Weigh When They Are Born?

West Highland White Terrier puppies are tiny at birth, weighing less than a pound. These little bundles of joy might seem impossibly small, but they don’t stay that small for long!
By the time they are 3 months old, Westie puppies will weigh between 6 and 9 pounds.
At What Age Are Westies Full Grown?
As a smaller breed, Westies tend to grow fairly quickly. Their growth can be broken down into two main phases: height and weight gain.
Height
Westies will most likely reach their full height of 9 to 12 inches between the ages of 6 and 8 months. During this time, you’ll notice that their legs grow longer and they become more proportionate to their body.
Weight
Although they reach their full height fairly early, West Highland Terriers continue to fill out and gain weight until they’re between 12 and 18 months old. During this time, their muscles will develop, and they’ll achieve their adult physique.
It’s important to monitor your Westie’s growth and ensure they’re on track. Regular check-ups with your vet will help you stay informed about their development and address any concerns that might arise.
Remember that every dog is different, and some Westies may grow slightly faster or slower than the average timeline. As long as your puppy is healthy, there’s no need to worry if their growth doesn’t perfectly align with these guidelines.
Size Difference Between Male and Female Westies
When it comes to Westies, size does matter—especially when you’re comparing males and females.
While both genders share many of the same personality traits, there are some distinct differences in their size and build.
Male Westies
Male Westies are generally larger than their female counterparts. Here are some key characteristics to keep in mind:
- Height: Males typically stand between 10 and 12 inches tall, giving them a slightly taller stature compared to females.
- Weight: Male Westies usually weigh between 15 and 22 pounds, reflecting their more muscular build.
- Build: Speaking of muscles, male Westies often have a more robust and muscular frame, which contributes to their higher weight. This includes a larger head, which is another distinguishing feature of male Westies.
Female Westies
Female Westies, on the other hand, are generally smaller and more petite than males. Here’s what you can expect in terms of size and appearance:
- Height: Females usually measure between 9 and 11 inches tall, making them a touch shorter than male Westies.
- Weight: Female Westies typically weigh between 13 and 16 pounds, reflecting their smaller and more delicate build.
- Build: Overall, female Westies have a more slender and dainty appearance, with a more petite frame compared to males.
Male and Female West Highland Terrier Growth Charts
Age | Weight (Male) | Weight (Female) |
0 months | < 1 pound | < 1 pound |
3 months | 6 – 9 pounds | 6 – 7 pounds |
6 months | 10 – 16 pounds | 10 – 11 pounds |
9 months | 13 – 18 pounds | 11 – 13 pounds |
12 months | 15 – 20 pounds | 12 – 15 pounds |
18 months (full grown) | 15 – 22 pounds | 13 – 16 pounds |

These size differences are generalizations and individual Westies can vary. Some females might be larger than males, and vice versa.
As you can see from the charts above, Westies stop growing around 18 months of age.
As long as your Westie is healthy and within the normal size range for their breed, there’s no need to worry if they don’t perfectly match these descriptions.
Assessing Your Westie’s Weight
Keeping your Westie at a healthy weight is crucial for their overall health and well-being. A dog that’s too thin or overweight can experience various health issues, such as joint problems, heart disease, or diabetes.
Is My Westie Overweight?
To check if your Westie is carrying a few extra pounds, follow these steps:
- Place your hands on their ribcage, with your thumbs on their spine and your fingers on their sides.
- Gently press down to feel their ribs. If you cannot feel your Westie’s ribs, they might be overweight.
Here are some tips to help your Westie lose weight:
- Consult your vet for guidance and to rule out any underlying health issues.
- Adjust their diet, focusing on high-quality dog food in appropriate portions.
- Substitute your dog’s rewards for low-calorie dog treats.
- Increase their exercise, such as adding an extra walk or play session each day.
- Monitor their progress and adjust their routine as needed.
Is My Westie Too Thin?
To determine if your Westie is underweight, follow the same steps as above to feel their ribs. You should be able to feel them, but they should not be protruding.
Because Westies have a thick double coat, if you can see your Westie’s ribs without even touching them, they might be underweight.
Here are some tips to help your Westie gain weight:
- Consult your vet to rule out any health issues and get personalized advice.
- Adjust their diet, ensuring they’re getting enough calories and nutrients from high-quality dog food.
- Consider adding healthy treats and supplements as recommended by your vet.
The Takeaway
Understanding the growth and size differences between male and female West Highland White Terriers is essential for any Westie owner. By monitoring your Westie’s growth from puppyhood to adulthood and regularly assessing their weight, you can ensure they’re healthy and thriving.
Remember that every Westie is unique, and it’s important to talk to your veterinarian if you have concerns about your dog’s growth, weight, or overall health.
By providing proper care and attention, you’re helping your Westie live their best life, filled with joy, love, and plenty of adventures!