How Old Is My Jack Russell In Human Years?

jack russell age human years

It’s hard to own a Jack Russell for one minute without hearing the rule of thumb that 1 year in the life of your pup is equal to 7 years of your life. If you have ever doubted this timeless wisdom, it’s time to weed out those doubts and replace them with pure dog love.

The math behind the first year of a Jack Russell puppy’s life is easy: 1 dog year equals 15 human years. For the 2nd year, you need to add 9 more years, and for each year after that, you need to add 4 more years.

Jack Russell Age Calculator

Here is a Jack Russell age calculator chart that you can use for easy reference.

Age of Dog Age in Human Years
1 15
2 24
3 28
4 32
5 36
6 40
7 44
8 48
9 52
10 56
11 60
12 64
13 68
14 72
15 76
16 80

How to guess your Jack Russell’s age

All dogs have teeth, of course, but they all develop them and lose them at different times throughout their lifespan. This guide should give you a relatively accurate idea of how old your dog is looking at its teeth. It’s not 100% accurate, though.

8 Weeks

Puppies start teething at 8 weeks old when baby teeth first begin forming. A lot of people believe that Jack Russells don’t have baby teeth. This is actually false. These “baby” teeth are important because they help Jack Russells develop the correct jaw muscles that will be needed to chew solid food as an adult.

12 Weeks

At 12 weeks, your pup will have all their baby teeth and are ready to start teething on adult teeth.

7 Months – 1 Year

Your Jack Russell’s adult teeth have appeared. The milk teeth (the short pointy ones at the front) should be all gone by now, too.

1 Year – 2 Years

Teeth are duller and the back teeth may have some yellowing.

3 Years – 5 Years

At 3 Years – 5 Years, your Jack Russell really starts to show his age. One of the biggest changes in regards to your dog’s teeth at this time is the amount of tartar buildup.  Tartar can’t be prevented if you don’t brush your dog’s teeth regularly, but good dental care can ward off decay.  You’ll want to brush your dog’s teeth at least once a week in order to prevent tartar buildup.

5 Years – 10 Years

Your dog will have slightly worn teeth with more signs of wear and tear. It’s still important to brush their teeth at least once a week, as well as check for deterioration and infections.

10 Years+

You’ll probably notice that your dog’s teeth are not very clean anymore. It is likely that they may have gum disease or loose back molars at this stage.

How long do Jack Russells live on average?

A Jack Russell’s life span can realistically be 13-16 years and some having the potential to live as long as 17. Depending on the specific characteristics of an individual dog, it is theoretically possible for them to live up to 17 years of age. This is rare, however, and not very common.

How To Take Proper Care Of An Older Jack Russell

Some Jack Russells can live as long as 17 years, but that doesn’t mean they’re not aging. In fact, old age is a very important period in the life of your dog. This is the time when you must take extra care of your faithful companion in order to make sure that they are happy and healthy. You should be aware of some changes which happen with age and how to deal with them accordingly.

You may need to have a vet examine the dog for any signs of disease or discomfort. Some old age problems include an increased reluctance to exercise, decreased appetite, excessive thirst or urination, vomiting, and loss of coordination (a common problem for older dogs).

1. Prevention Is The Best Medicine

Prevention is always better than treatment. Before you know it your dog may suffer from disease or other health issues that will require more care and attention. Through proper care, you will make sure that your Jack Russell has a long, happy, and healthy life. If you have a puppy or older dog, then be sure to spend time with your dog and take care of its health needs when necessary.

2. The First Signs Of Problems

Be aware of your dog’s health and don’t ignore any symptoms. Your dog might not show all the symptoms at once, but if you watch for signs that something is wrong you will be able to take care of them before they become severe. In this case, your dog could suffer from everything from obesity to a heart condition, but it could still live a long and healthy life if the issues are treated early.

3. Diet Is Key To Good Health

If you want your Jack Russell to be healthy and live a long time there is one thing that you must consider; diet. Be sure to feed your dog a diet that is high in protein and low in carbs. If you don’t you may end up with a dog that is overweight and suffers from diabetes. Diabetes can cause blindness, but there are treatments to prevent or reverse the effects of the disease.

4. Aging Gracefully

As a Jack Russell gets older, it will be more susceptible to old age problems such as arthritis, thyroid problems, heart conditions, eye problems, and more. When this happens the owner will need to adjust their routine with their Jack Russell. If the Jack Russell is ignored and not given the proper care it will be harder to recover.

5. Heart Problems

The Jack Russell has a very strong heart that will overcome most issues, but small problems such as a heart murmur can present themselves to lead to fatal conditions if care is not taken. It is important to take your dog to a veterinarian if there are any signs of heart problems to prevent further complications. Although your dog may live long enough without heart problems, they will be living a shorter life than normal because of it.

6. Infections

Infections are the main cause of death for older dogs. If your Jack Russell becomes infected with disease, then the vet may have to prescribe antibiotics to cure the problem. Antibiotics can be very harmful to your dog’s body if they are abused and overused. Be sure to follow the instructions of how often you should give your dog antibiotics and what not to do while using them.

7. Eye Problems

Another common issue that people don’t pay attention to in their dog is eye issues. Conditions such as cataracts, glaucoma, and dry eye can lead to blindness if not taken care of quickly. This is why it is so important to take regular trips to the vet so that they can check your dog’s eyes and make sure that there are no problems or signs of a potential problem developing.


Have you ever heard the phrase “one dog year equals seven human years?” If you’re a dog lover, you probably know this saying is used to describe how long a dog lives when compared to a human.

The origin of this popular saying is still unknown, but everyone from veterinarians to dog owners believes in it.

Hopefully, now you have a better understanding of how your Jack Russell’s age relates to human years.


  • Jan Pretorius

    Meet Jan Pretorius, the passionate dog lover and proud owner of the popular canine haven, Born and raised in a small town known for its love of animals, Jan’s journey into the world of dogs began at a young age, fueled by an innate connection with our four-legged companions.