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Your Dog Is Older Than You Think. Science Suggests a New Formula to Translate Canine Age

The oldest dog in the world lived for more than 29 years. It would be even more impressive to calculate this number in human years, and at this point there is only one issue — the formula. Luckily, scientists can help us with this study. And it’s not about 7 year rule anymore.

We at Bright Side have already calculated how old our dogs are. And we’re asking you to join us. The results will surprise you.

Different ages

We need to know that there are several understandings of how dogs age. Chronological, which means specific timing from their moment of birth and biological, which is based on changes in the body. These values ​​may vary and in order to understand the age of the dog, biological indicators are more important.

Different breeds

The breed of a dog also plays an important role in aging. First, it affects their life expectancy. Small dogs live longer than large ones. And second, this factor affects the age at which the dog reaches maturity. Giant dogs achieve this later than other breeds.

Who was examined

Considering all the facts, it may seem that it's difficult to apply one universal formula to calculate the dog's age in human years. However, scientists have found a way to do this. They compared human data with Labrador Retrievers. They chose them because this breed is heterogeneous and has a huge variance in life expectancy.

What was examined

But how do you compare dogs with people? We're both mammals and we have a lot in common. And scientists decided to check biological aging using DNA methylation. This shows changes in DNA that happen during life. They examined human and dog DNA and found a way to match the ages. They also compared mice DNA with these results.


According to the results of matching human ages with dog ages, scientists have been able to develop a formula. This helped them calculate the human equivalent of canine years. Here it is:

Human age = 16 ln(dog age) + 31

We know this can seem complicated. Let us explain what this means. "In" is the natural logarithm. To calculate the age of your dog, you need to calculate the logarithm adding the chronological age of your dog. Afterward, multiply the result by 16 and then add 31. It's definitely not as simple as just multiplying by 7, but you can use this online calculator to figure out the logarithm easily. Or you can just look at the results that we’ve calculated for you:

  • 1 dog year – 31 human years
  • 2 dog years – 42 human years
  • 3 dog years – 49 human years
  • 4 dog years – 53 human years
  • 5 dog years – 57 human years
  • 6 dog years – 60 human years
  • 7 dog years – 62 human years
  • 8 dog years – 64 human years
  • 9 dog years – 66 human years
  • 10 dog years – 68 human years
  • 11 dog years – 69 human years
  • 12 dog years – 71 human years
  • 13 dog years – 72 human years
  • 14 dog years – 73 human years
  • 15 dog years – 74 human years

So when we use this formula we get that a 1-year-old puppy is like a 31-year-old human. And this differs a lot from what we used to know about dog aging. Of course, more studies are needed to check other breeds (besides Labrador Retrievers). But let's admit that no matter how old they are in human or dog years, they will always be our little adorable and spoiled puppies to us.

How old is your dog according to the new formula? You can write your results in the comments.

Preview photo credit Exclusivepix/EAST NEWS
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