A dog year equals seven human years - but is that really true?

Almost every Dog owner has ever wondered how old his four-legged friend is in dog years. In doing so, they often go back to a rule of thumb that says that seven dog years equals one human year. This calculation method was established after it was observed that an average-sized four-legged friend lived through approximately one seventh of the life of a person.

According to current research, the well-known rule of thumb for converting human years into dog years has turned out to be a myth. The updated version requires a little more math understanding, but is also more applicable.

The life expectancy of a dog

A dog's mind and body age faster than a human's. Nevertheless, there are considerable differences in this regard even among four-legged friends. Life expectancies for dogs vary depending on the breed. While a pug lives on average 12 to 15 years old, owners of a bulldog can only spend around 6 to 9 years with their four-legged friend.

In addition to breed, other criteria also play a role in a dog's life expectancy. Diet, the extent of daily activities and illnesses can lead to old age.

Even weight and size are crucial in estimating a dog's life expectancy. Basically, small, low-weight four-legged friends seem to live longer than large and heavy breeds.

On the other hand, no one can predict the age of an individual dog with any certainty. Regardless of all averages, the currently oldest female dog in the world, Maggie, was over 30 years old. She was an Australian Kelpie and therefore belonged neither to a small nor to a light breed.

Convert human years to dog years

Young dogs age significantly faster than humans. However, this process slows down as they age. Dog years and human years cannot therefore be compared with each other by simply adding them up.

The revised version of the “age + 7 years” rule reads according to the current state of research “16ln (dog age) +31”.
The abbreviation ln stands for a natural logarithm in which the exponent to a base is sought. It is, so to speak, the reverse of exponentiation.

For math amateurs, this formula sounds daunting at first. Nevertheless, every owner can calculate the age of his four-legged friend in dog years by using a calculator. The natural logarithm is there as a fixed key. Alternatively, the formula can also be entered in the search bar of a search engine.

The researchers who were involved in putting together this formula assume that dogs age at different rates depending on their stage of life. They found this out by comparing DNA patterns from several dogs with those from humans. Different age groups were represented among the four-legged friends as well as among the people.

With this approach they were able to derive the formula "16ln (dog age) +31".
If you follow this formula, a four-legged friend is already 31 dog years old after one human year. Three years later, on his fourth birthday, it was 53 dog years.

How far the research is on the subject of dog years

There are many other formulas and conversion tables on the Internet to convert human years to dog years. Some of them even take into account the size or weight of the dogs. They all agree that the seven year rule is oversimplified to give an accurate result.

We personally consider "16ln (dog age) +31" to be the best formula for converting human years into dog years.

The knowledge gained from the research and ultimately the formula for the conversion come from renowned biologists and geneticists at the University of California San Diego and are still fairly new. The researchers themselves do not consider their work in this field to be complete. So far, they have only examined the DNA patterns of Labrador Retrievers. A different formula may be required for dog breeds with different life expectancies.

In order to get more precise results, further investigations must therefore be carried out.

Nevertheless, the formula "16ln (dog age) +31" is very precise for the current state of research.

What good is it to be able to convert human years into dog years?

If you know the age of your four-legged friend in dog years, you can develop a better understanding of him. Before, you may have wondered when your dog after the joint walk had to recharge for hours or at training could no longer provide full performance. After all, he's only seven years old. According to the new formula, however, these seven calendar years are equivalent to 62 dog years.

It is also important for veterinarians to be able to calculate the age in dog years. This enables them to better make diagnostic and therapeutic decisions.

It is therefore very important that research in this area does not stop and that we can continue to collect new knowledge about our four-legged friends on a regular basis.