How Much Does a Jack Russell Terrier Weigh?

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The small size and friendly and affectionate nature of Jack Russell Terriers towards their owners make them a good choice for a lapdog. However, you might want to know how much a Jack Russell Terrier weighs before adopting one. So, how much does a Jack Russell Terrier weigh?

How Much Does a Jack Russell Terrier Weigh?

The average weight of an adult Jack Russell Terrier is around 13 to 17 pounds. A 3-month-old puppy weighs around 6 to 8 pounds, while a 6-month-old puppy weighs about 11 to 14 pounds. Usually, the weight of male JRTs is on the higher end of the weight spectrum.

However, the weight can vary depending on the diet, health condition, and whether the dog is purebred or mixed.

A Jack Russell terrier walking in the grass

Also, you can have taller JRTs depending on their ancestry history and gene combination. Considering the natural weight-to-height ratio, the larger JRTs tend to be heavier than their smaller counterparts. The following table provides a breakdown of different weights you can expect from JRTs of varying ages.

Age of the dog (Months)Weight (Pounds)
24 to 6 
36.2 to 7.9 
48.4 to 10.4 
59.9 to 12.8 
611 to 14 
712.3 to 15 
812.8 to 15 
912.8 to 16 
1013 to 17 
1113 to 17 
1213 to 17 

Since reputable breeders will only allow you to adopt a JRT puppy at least eight weeks old, you can confirm whether the puppy is between 4 to 6 pounds to know whether you are adopting a puppy with a healthy weight. Apart from the age, the weight of a JRT might vary due to:


JRTs are energetic and hyperactive dogs, and you’ll need to engage them in rigorous exercises to help them use the excess energy. A JRT that engages in rigorous physical activities will burn calories and have a healthy weight.

On the other hand, a JRT that doesn’t exercise will accumulate fat and become overweight. Once the dog starts gaining weight, the rate of fat accumulation increases as the dog will be more unwilling to exercise, eventually leading to obesity.

Jack Russell terrier playing on grass field

Ancestry History

In most cases, the weight of a JRT will vary depending on the ancestral history. That means you can use the weight of the dog’s parents to predict the future weight of your JRT. The weight can also vary depending on the dominant genes if the dog is a mix.


The amount and type of food you feed your JRT directly impacts its weight. If you underfeed your dog or you don’t feed it with nutritious foods, it will be malnourished and become underweight. 

Malnutrition in puppies can lead to stunted growth and make them prone to health conditions that can affect their weight in the future.

How to Know Whether Your JRT Has a Healthy Weight

Knowing whether your dog is overweight or underweight can be challenging, especially if you’re a new dog owner. Regardless of your dog’s age, you can use the following tips to determine whether your dog has a healthy weight.

  • Check the overall shape of your dog: You can tell whether your dog is overweight or not by checking the overall shape, especially around the belly area. If the dog’s sides seem straight with the waist contracting towards the rear, the dog has a healthy weight. If the dog is oval-shaped, then the dog is obese.
  • Feel the ribs with your hand: Use your hand to feel the prominence of the ribs. If you can feel the dog’s ribs without struggling to press on a layer of fat, then the dog has a healthy weight.
  • Pay attention to the dog’s behavior: JRTs are generally active and playful dogs. If the dog is unwilling to play and exercise or gets exhausted after a short exercise time, there are chances it’s overweight.
  • Pay attention to the fat pads: If the dog is excessively obese, fat pads can form on the hips or fat sacks between the legs. In most cases, the dog will also have trouble walking and breathing.
Jack Russell terrier sun bathing

Related Questions

Why Is My JRT Drinking Lots of Water Yet It’s Losing Weight?

The main reason why a JRT can drink lots of water and continue losing weight is diabetes mellitus and kidney failure. It’s advisable to contact a veterinarian to help carry out blood tests and determine the underlying health condition.

Can Worms Make My JRT Underweight?

Worms can make JRTs underweight as they are internal parasites that feed on the nutrients in the intestines. Usually, a JRT with worms will have other signs such as loss of energy, excessive hunger, poor coat, and diarrhea.

In case of severe diarrhea, the dog’s bottom can also become sore.

Final Thoughts

Although JRTs will have different weights depending on their age, ancestry history, and diet, you can tell whether your dog has a healthy weight by looking at its body shape and behavior. If your dog is overweight, consider engaging it in intense exercises to help it burn calories.