Dog Age Calculator: New Way to Calculate Your Dog’s Human Age

Dog age calculatorAre you looking to calculate your dog’s age in human years?

A new equation has been proposed by researchers at the UC San Diego School of Medicine in a 2020 scientific report in the journal, Cell Systems.

In the past, dog owners would multiply their dog’s age by 7. However, that formula has never had any scientific support.

I had a dog age calculator created with the new formula (below) to calculate how old your dog is in human years.

Keep in mind, there are some limitations to this new formula, which are explained in this article.

Dog Age Calculator To Determine Human Age

If you want to skip the background information, here’s the calculator to test out the new formula:

What’s the New Formula to Calculate A Dog’s Human Age?

The new formula to calculate a dog’s human age is 16 ln(dog age) + 31.

To break it down, this means you take 16 and multiply it by the natural logarithm of your dog’s age and then add 31.

There is usually a button on a calculator to determine the natural logarithm of a number. However, here’s some further info behind it:

  • A logarithm is essentially how many of one number (the base) you need to multiply to reach your desired number. For example, the logarithm of the number 8 with base 2 is 3. This is because if you multiple 2 x 2 x 2, you get 8, so you needed to multiply the base 2 (3 times) to reach 8.
  • The natural logarithm (abbreviated ln) is how many times you need to multiply base “e” (Euler’s number of approximately 2.718281828459) to reach your desired number. For example, the natural logarithm of 7.389 is around 2 since when you multiply 2.718281828459 by 2, you get 7.389.

Background of the New Formula

Scientists studying methylation of dog dnaThe researchers at UC San Diego studied the concept of DNA methylation. This is where a mammal’s DNA develops chemical marks as they get older called “methyl groups”, which attach to their DNA.

This methylation happens at a predictable rate as humans age and allows for the estimation of a person’s age, which is called the epigenetic clock. These methyl groups show up at different stages of a mammal’s life such as birth, infancy, youth, puberty, adulthood, and old age.

The researchers compared the methylation rate patterns of 104 Labrador Retrievers to humans, in addition to mice. After comparing the patterns, the researchers were able to determine a formula of how dog years compare to human years.

The methylation rates of dogs and humans were shown to be similar in some parts of life but different in others. For example, in their very early stages, 7-week old puppies develop their first teeth just like young 9-month old babies. However, dogs mature much faster than humans and can have puppies when less than 1 years old. Then a dog’s clock slows down and better matches up with humans later on life.

For example, based on the new formula, a 2-year old dog is 42 years old in human years. This is compared to the old formula where a 2-year old dog is only 14 in human years (2 times 7).

Limitations of New Formula

This new formula was determined from only one breed: the Labrador Retriever. The researchers analyzed Labradors ranging from 4 weeks old up to 16 years old.

However, it’s known that different breeds age differently. Additional, while most mammals have a longer life expectancy with a larger size, the opposite is true for dogs. Small breed dogs tend to age more slowly, while big dogs age quicker. As a result, small breed dogs tend to live longer.

It’s predicted by Trey Ideker, PhD, a professor at UC San Diego School of Medicine, that the formula will work with all dog breeds. However, further research needs to be performed.

Additional Methods to Calculate Your Dog’s Age In Human Years

Photo of person typing in calculatorPrior methods to calculate your dog’s age in human years don’t seem to match up well with the new formula.

For example, the American Veterinary Medical Association (“AVMA”) previously gave the following estimation (although I can no longer find it on their site):

  • The first year of a medium-size dog’s life equals 15 human years.
  • In the second year, it adds another 9 human years.
  • After the second year, every additional year equals 5 human years.

It’s possible that they eliminated this estimation after the new research from UC San Diego came out.

When viewing their current site, they offer a different age chart showing the human year equivalent for various senior aged dogs. According to the chart:

  • Dog ages of 7 equal human ages of 44 to 56 yrs old*
  • Dog ages of 10 equal human ages of 56 to 78 yrs old*
  • Dog ages of 15 equal human ages of 76 to 115 yrs old*
  • Dog ages of 20 equal human ages of 96 to 120 yrs old*

*These ranges vary depending on the size of your dog from small (0 to 20 lb), medium (21-50 lb), large (51-90 lb) and very-large (>90 lb).

Ways to Help Your Dog Live Longer

1. Have them maintain a healthy body weight

Drawing of happy running dog with bone in mouthAccording to the Association for Pet Obesity Prevention, an estimated 56% of dogs in the U.S. were considered overweight or obese in their 2018 study. Dogs who are overweight have a shorter lifespan than dogs with healthy dog weight. Both diet and exercise can both play a part in keeping their body weight in check.

2. Regularly visit your vet

With annual wellness exams, you can catch issues early for better prevention and treatment to prolong your dog’s life. With senior dogs, it is often recommended to go semi-annually due to age-related injury and illnesses.

3. Give them regular exercise

Just like with humans, exercise can help reduce stress and improve mood for dogs. Exercise also helps them maintain a healthy body weight. While it will vary on the breed and age, it’s often recommended for dogs to get at least 30 minutes of exercise each day.

If going outside is a problem, you may want to look at dog treadmills as a potential option.

4. Healthy diet

There is much debate on what foods to feed dogs to increase their lifespan such as fresh food, regular kibble, raw food, etc. However, it’s fairly accepted that dogs who eat less live longer.

With the right high-quality dog food, you can improve your dog’s immune system, maintain their joints and muscles, improve their intestinal health, and more. Speak to your vet on the best foods for your dog.

Conclusion on Dog Age Calculator

Well, I hope you tried out my dog age calculator to calculate your dog’s human age.

As discussed, the formula of this calculator is built upon scientific research from UC San Diego.

While there are some possible limitations to the new formula, it has a lot more support than the old formula of 1 dog year to 7 human years.

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