We often have our dogs from puppyhood through their senior years. Have you ever wondered how your dog’s age relates to your age? Having a general idea can help you understand what they are experiencing both physically and emotionally so you can provide them with the support and training they need at each stage of their lives.

How To Convert Dog Years to Human Years

The generally accepted rule has always been that one human year equals seven dog years, but other factors impact this equation, such as breed, weight, size and the fact that each dog is unique in their genetic makeup. Additionally, during the first two years of a dog’s life, they age and develop more quickly than their later years. You can get more accurate than the “rule of seven” using your dog’s expected full-grown weight and a little math.

Here is how you can loosely map out your dog’s age in human years:

• For all sized breeds, the first dog year equals about 15 human years.

  • Your dog’s first eight weeks are equivalent to a human’s first nine months of life.
• By your dog’s second year, for all sized breeds, they’re approximately 24 human years old.

At age three, your dog’s size becomes a factor. Use your dog’s expected weight when their full-grown to find the most accurate conversion.

• Small dogs 20 lbs or less. Add four human years for every dog year. Three dog years = 28 human, four dog years = 32 human, and so on.
• Dogs 21-50 lbs. Add four years for age three (28 human years), five years for age four (33), four years for age five (37), five years for age six and seven (42 and 47). From this point, it alternates between four and five years. Age eight = four years, age nine = five years, age 10 = four years, age 11 = five years, and so on.
• Dogs 51-90 lbs. Add six years for age three (30). Then, add five years for each dog year four through eight (35-55). At this point, it alternates between five and six human years for each dog year. Age nine = six years, age 10 = five years, age 11 = six years, and so on.
• Dogs over 90 lbs. Add eight years for age three (32). Add five years for ages four and five (37 and 42). Add seven years for age six (49). From here, the breakdown is + seven for dog year seven, + eight for dog year eight, + seven for dog year nine, + seven for dog year 10, + eight for dog year 11, + six for dog year 12, + eight for dog year 13, + seven years for dog year 14, + seven years for dog year 15, + 17 years for dog age 16.

Keep in mind these are general guidelines to approximate your dog’s age in human years. Many factors impact the true calculation. General is as close as we can get.

What is the Average Lifespan of a Dog?

Though the specific wolf population that dogs are descended from is extinct, our present-day dogs’ lives are now greatly prolonged thanks to high-quality diets, preventive care, advanced veterinary care, and their living conditions. A study conducted from 2013 to 2019 showed a 5% to 6% increase in their lifespan¹.

Here are some things that can impact your dog’s lifespan:

Breed

There are certain health issues, such as cancer, joint disease, or heart disease, that some breeds are predisposed to. Studies show that purebred dogs suffer from medical issues at a younger age and can die at an earlier age compared to mixed-breed dogs². Genetic defects can also develop from poor breeding. Development of any health issue, especially more than one, can shorten the lifespan of a dog.

Spay and Neuter

Studies have shown that the life expectancy of spayed and neutered dogs is longer than intact dogs. A spayed dog’s life expectancy was 26.3% longer, and a neutered dog’s 13.8% longer³. Specific health benefits include decreased roaming, fewer behavioral issues, decreased chances of reproductive health issues, and preventing certain infections and cancers.

Environment

The safety and stability of a dog’s environment can impact their longevity, as can their access to regular veterinary care.

Diet and Body Weight

To support their overall health, it’s important that dogs receive a well-balanced, high-quality diet that provides all the essential nutrients they need. Feeding the correct amount based on your dog’s age to maintain their ideal weight is also vital. A study found that overweight dogs have an estimated six-month to two-and-a-half-year decrease in average lifespan⁴.

Dental/Body Connection

Studies show that some form of periodontal dental disease exists in 80-90% of dogs over three⁵. A dog’s lifespan can be shortened by dental disease as the bacteria that cause infection within the mouth can spread to the rest of the body. This can cause or worsen heart, liver, and kidney disease, as well as make management of diabetes difficult. Discuss with your veterinarian what a good home dental care regime would be for your dog, as well as how often your dog should have a dental cleaning under anesthesia.

Regular Veterinary Check-Ups

From the start of your dog’s life, you want to prevent health issues before they start. Your puppy can avoid certain diseases and health problems with regular examinations, vaccines, and preventive care. As your dog continues throughout their life, especially during their senior years, regular veterinary check-ups allow for the early detection and treatment of medical conditions in the early stages, which improves outcomes.

Converting dog years to human years isn’t as straightforward as many of us were led to believe, but a dog’s lifespan can be affected by a variety of factors. As pet parents, we do our best to help our fur babies live the longest, happiest lives they can.