Dog Age Chart: Discover Age in Human Years by Size

Many of us have been told that one dog year is equal to seven human years. Though we’ve used this formula for years, studies now show that this comparison is not accurate.

Today, we break down recent studies on the canine aging process, and help you better determine just how old your pup is in human years!

Let’s get started.

How Quickly Do Dogs Age? Here’s What Science Says!

We have been told for many years that dogs age at a rate of seven years for every human year. While we know that dogs age much faster than you and I, this seven-year rule is not quite accurate.

Experts now believe the ‘7-year rule’ may have been created in an effort to stress the importance of regular health checks due to how quickly our canines age. Thankfully, researchers have found a more accurate way to determine a dog’s age in human years.

Researchers examined the aging process in both humans and dogs by comparing their DNA. They looked for patterns in each of their DNA and examined how these patterns changed over time. By doing this, they came up with an accurate formula to determine a dog’s age in human years.

(human_age = 16ln(dog_age) + 31)

Let’s Make That Easier!

This formula is pretty complex, so let’s break it down! According to the American Veterinary Medical Association (AVMA), this is how you can best determine your dog’s age in human years:

• The first year of a dog’s life is equal to 15 human years
• The second year of a dog’s life is equal to about nine more human years
• Once they reach three years of age, each additional year is equal to five human years

Keep in mind that the above rule roughly applies to small and medium sized dogs, so larger canine friends will age at a faster rate once they reach six years of age.

Dog Age Chart – Age in Human Years by Size

We’ve created an easy-to-follow chart to help you determine your dog’s age:

Why Do Large Dogs Age Faster Than Small Dogs?

Research is still ongoing as to why small dogs seem to live longer than large dogs. Some scientists believe that since large dogs experience accelerated growth at the beginning of their life, they may be at risk of abnormal cell changes in their senior years. However, this theory is not yet proven.

Maybe one day we will have the answer!

Things To Keep in Mind as Your Dog Ages

Since our canine friends age at a much faster rate than you and I, it’s important to have your dog assessed by a vet regularly. We suggest scheduling a wellness exam with your vet once a year until the age of seven, and twice a year from eight years of age and on.

Yearly wellness exams can help your vet detect any changes in health, as many health complications are challenging for pet owners to detect on their own. Your vet will also recommend annual senior blood testing once your dog is eight years old, as dogs have an increased risk of health decline once they enter their senior years.

Final Thoughts

As we discussed above, a dog’s first year of life is equal to 15 human years. Their second year is equal to about nine more years, and each additional year after that is equal to five human years.

Be sure to check out the chart above to figure out just how old your pup is in human years!