How Many Dog Years In Human Years?

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As human beings, we celebrate our birthday every year, every 365 days. It signifies how old we are already living in this world since birth, and it also tells us how the human years work. But this is not the case for the dog when they celebrate their birthdays.

Many of us know the 7:1 ratio that seven years of a human is like one whole year for the dogs. According to scientists, this age calculation between humans and dogs is not accurate. So how do we know the exact number of years of dogs in human years?

Dog Size And Breed Does Matter

The size of a dog plays a vital role. It happens that smaller dogs live longer than the bigger ones. The average lifespan of a small breed of dog like Pomeranian is 12 to 16 years, while the average lifespan of the largest breed of dog St. Bernard is only 8 – 10 years. It proves that the dog’s life span depends on the maturity of the breed and the size.

Smaller dogs may mature faster in their early years, but they live a longer life. While Larger dogs might age and mature slowly at first, but they grow old fast in middle age and live a shorter life. Though scientists baffled them for years, research has yet to explain this phenomenon. It says that the relationship between the size of the dog and breed has something to do with a dog’s lifespan.

History Check

Bluey is the oldest Dog to ever live in the world, as recorded by Guinness. It is an Australian Cattle Dog born in 1910 and died in the year 1939 at the age of 29 years and five months. But recently this year 2016, a Dog named Magie, a Kelpie Dog who is coincidentally also from Australia, died at the age of 30. These two farm dogs are the oldest dogs recorded in history.

The Early Way To Convert Dog Years In Human Years

During the 1950s, A french researcher name A. Lebeau recognized that calculating and converting human years to dog years is not that simple. Lebeau knows that dogs mature and gets old faster than a normal human being. The age of Dogs is not constant like humans on how they celebrate their birthdays every after 365days. So multiplying the age of a dog by seven human years doesn’t always work accurately.

Only by looking at a dog’s maximum life span and human’s life-stage marker like childhood, adolescence or puberty age, adulthood to old age, Lebeau created this system to calculate the dog years and human years and the scientists think that it is more accurate than simply using the 7:1 ratio for humans and dogs.

Another researcher named Dr. Kathryn McGonigle realized that dogs reach adulthood during the first two years or within the first two years of their lives. Every year after that is equal to roughly four years if human and not seven. Because usually a human being reaches and starts adulthood stage at the age of 20.

Dr. Katrhyn stated that “Aging is very different across species, and it is true that dogs and cats age faster than humans do. You may have an infant pet, his teens, preteens, and become an adult by the age of two” Dr. Kathryn McGonigle formulated that the first two dog years is “the first 15 to 24” human years.

The Official Formula

According to the American Veterinary Medical Association, this official formula for calculating the age of a dog in human years. The 15 human years equates to the first year of a medium-sized dog. The dog’s second year is equal to 9 years of a human. Then afterward, every year for a dog feels like five years.

The formula still varies depending on the size of the dog and the weight of the dog. As mentioned a while ago, larger dogs have shorter lives and faster in dog years, and smaller dogs live longer and age slower in dog years.

But this formula has changed over time because of the major factors like the change in human life expectancy. Before, the life expectancy of a human born in 1901 was 49 years. And now the life expectancy of a human born this year 2019 is 75 years. The same goes for the Dogs. In 1987, 32% of dogs lived for about six years. Now about 44% live longer.


Determining dog years in human years by using a 7:1 ratio is not an accurate formula. You can use many different ways, like the old formula and the official one. And as a dog owner or a dog lover, you’ll know it by heart.

Humans love dogs, who can deny the fact that dogs are close to a man’s heart? Dogs instantly become your stress reliever, the source of your joy, and sometimes a family to you. Our dogs helped us grow personally in our lives, and as we grow old, we sometimes forget that they’re also growing old and fast. Many of us wanted our dogs always to leave us.

Many have wished that our dogs will live long years of life like humans. But it is a sad reality that a time will come humans and dogs will part ways in this mortal world. So make every moment count with your Dog. Thank you for reading.

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