Reality Or Myth: One Dog Year Equals Seven Human Years

Reality Or Myth: One Dog Year Equals Seven Human Years

Last update: 25 April, 2018

Throughout our lifetime, we have repetitively heard people say that one dog year equals seven human years. Since this statement is considered to be true, we often repeat this statistic. However, where does this information come from? On what evidence is it based on? Today, we will examine the myth versus reality on this subject.

Why is the saying that one dog year equals seven human years considered to be a myth?

one dog year equals seven human years

The one dog year equals seven human years rule became popular during the last century. Nevertheless, no one has claimed ownership over this statement. So, we are definitely facing a myth. Let’s try thinking about this false axiom.

The first thing that needs to be looked at is the form and speed of a dog’s aging. A homogeneous criterion cannot be set due to the large amount of existing breeds. 

As matter of fact, this is what has always been said:  you cannot measure everything with a ruler. After all, we are not the center of the world. Dogs and humans grow and age differently. So,trying to match both is a big mistake.

The belief that one dog year equals seven human years seems to be true. It is repeated often without being verified. In reality, it is a myth of unknown origin. The truth is that canines age at a different speed than humans, based on their size and breed.

Reasons to debunk the 7 to 1 rule, or vice versa

Below are the reasons why it should be considered a myth:

  • Canines reach sexual maturity around the age of one. As humans, we obviously do not reach sexual maturity at the age of 7.
  • In their first years, dogs can age 20 years faster than people. Afterwards, this speed starts to decrease.
  • Larger size dogs live less than smaller breeds. The reason for this difference cannot be fully explained. In addition, the following is a fact that contradicts this frequent tendency in nature: a small size animal has a shorter lifespan.  For example, giant century old tortoises and rats which only live up to 2 years.
  • Smaller canines grow much faster than larger ones during the first few years.  Nevertheless, this process decreases as they get older. Although it seems strange – – at the age of two – – a small dog is much older than a large size dog at the same age. Although, it is younger at the age of 5!

How to calculate a dog’s age compared to a human

Here are some examples to give a more precise explanation on age difference between humans and dogs:

  • Two human years would equal 23 years in small breeds. This number is reduced to 20 in large breeds.
  • The debunking still continues, because 7 human years would be 44 years in small dogs, 47 in medium sized dogs, 50 years in large dogs, and 56 in giant dogs.
  • Also, just one more comparison to make a long story short: 13 human years would equal 68 years in small dogs, 74 in medium-sized dogs, 82 in large dogs, and 101 in giant-sized breeds.

Properly take care of your dog during each stage of its life 

one dog year equals seven human years 2

So, stop clinging to the belief that one dog year equals seven human years. This type of thinking can lead us to make wrong decisions regarding our pets. 

Above all things, remember that the development of a dog’s life is not linear, and it changes depending on their size and breed.

Therefore, it is best to check with a veterinarian. A professional is much more qualified to give advice about how to properly take care of your pet during each stage of life.

After all, nothing is guaranteed in life. That is why it is important to love our four-legged friends daily.  No matter how long they live.  One thing that´s true: your dog would care less about the age of his owner!


The contents of My Animals are written for informational purposes. They can't replace the diagnosis, advice, or treatment from a professional. In the case of any doubt, it's best to consult a trusted specialist.