It is common knowledge that one year of a dog’s life is equal to seven human years… or not? If that’s how you calculated your dog’s age, don’t worry—you’re not alone. However, the truth is that this method is not entirely accurate.
Historically, it is likely that the “one dog year equals seven human years” method was created simply to show that dogs age faster than humans. Today, scientists and researchers have developed a more accurate method of calculating a dog’s age in human years.
Let’s dig in…
How do I calculate my dog’s age in human years?
If you want to more accurately calculate your dog’s age in human years, you can use a new formula created by researchers at the University of California, San Diego .
These researchers studied how human and dog DNA changes over time by studying patterns called methyl groups in humans and Labrador retrievers. From this research, they concluded that you can calculate a dog’s age in human years by multiplying the natural logarithm of the dog’s age by 16 and adding 31. Their formula is (human age = 16ln (dog age) + 31). As you can see, this formula is quite complicated.
For an easier and more accurate way to estimate your dog’s age, you can follow this technique for small, medium and large dogs weighing less than 45 kg:
- 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 approximately nine human years.
- Each additional year is equal to about four or five human years.
So why is it more accurate than the one dog year equals seven human years method?
Because he takes into account that not all dog breeds age equally. In general, smaller dogs live longer than larger dogs, so while a seven-year-old Great Dane may be considered an “older” dog, this is not necessarily true of a seven-year-old Chihuahua. Therefore, it is useful to break down the age table of dogs by size, as you will see below. Generally, you can divide dogs into small dogs (under 9 kg), medium dogs (9 to 22 kg), large dogs (22 to 45 kg) and giant dogs (over 45 kg).
Check out the dog and human age chart below to calculate your dog’s age in human years based on their size group:
| Вік собаки | < 9 кг | 9 – 22 кг | 22 – 45 кг | > 45 кг |
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 3 | 28 | 28 | 28 | 31 |
| 4 | 32 | 32 | 32 | 38 |
| 5 | 36 | 36 | 36 | 45 |
| 6 | 40 | 42 | 45 | 49 |
| 7 | 44 | 47 | 50 | 56 |
| 8 | 48 | 51 | 55 | 64 |
| 9 | 52 | 56 | 61 | 71 |
| 10 | 56 | 60 | 66 | 79 |
| 11 | 60 | 65 | 72 | 86 |
| 12 | 64 | 69 | 77 | 93 |
| 13 | 68 | 74 | 82 | 100 |
| 14 | 72 | 78 | 88 | 107 |
| 15 | 76 | 83 | 93 | 114 |
How do dogs age?
As you can see in our dog age chart, except for the giant category, small, medium and large dogs age about the same until they are six years old. In addition, larger dogs age much faster than their smaller and medium-sized counterparts. By the age of seven, a small dog such as a dachshund will be six human years younger than a large breed such as an Airedale terrier. Why is this?
After all, scientists aren’t entirely sure why small dogs age more slowly and live longer than larger ones. According to American Kennel Club, some researchers suggest this is due to the fact that larger dogs are more prone to age-related diseases. Similarly, large dogs go from puppyhood to adulthood much more quickly, which increases the likelihood of abnormal cell growth, cancer, and other diseases. That is why the use of the calculation “one dog year is equal to seven human years” is not entirely accurate.
Although the new method we shared is more accurate, it is still difficult to establish a general formula for how dogs age, as this progression will depend not only on the size of your dog, but also on his breed and individual genetics.
What are the common signs of aging in dogs?
So it can be helpful to look at physical and behavioral signs to determine your dog’s age. For example, teeth can be a particularly useful indicator of your dog’s age. By seven months, your dog will have all of its permanent teeth through, by 1-2 years they will be duller and may turn a little yellow, and by 5-10 years they will show wear and possibly signs of disease.
Other indicators of your dog’s age, especially as he gets older, include:
- gray hair
- poor eyesight, cloudy eyes
- hearing problems
- muscle and joint stiffness, arthritis
- low activity level
- behavioral changes such as increased anxiety, confusion, accidents at home, irritability, etc.
Of course, you can always consult your vet for an accurate estimate of your dog’s age if you are unsure. Your vet will look at factors such as teeth, body shape, coat, eyes, etc. to give the best estimate of their age.
Why is it important to understand the age of your dog?
Using a dog age chart to estimate your dog’s age in human years is a fun and informative way to learn more about your dog! This is important for other reasons. Namely, understanding how old your dog is and how it ages allows you to properly care for it and help ensure it has the best possible life.
Keep in mind that if you have a large dog, you should start looking for signs of aging around five or six years of age, while owners of small dogs may not notice any real signs until their dog is seven or eight years. Either way, as your dog gets older, you’ll need to keep a very close eye on his behavior, activity level, and eating habits. In general, a healthy diet and weight, constant mental stimulation and physical activity, and regular vet checkups will help increase your dog’s lifespan. Additionally, you may want to consider investing in pet health insurance to cover unforeseen accidents and illnesses. After all, your dog deserves the best care no matter how old it is.
Conclusions
After all, although the common method of “one dog year equals seven human years” has been around for many years, it is not very accurate. Fortunately, thanks to new research, we now have a more accurate way to estimate the age of our dogs.
Although the math can be a bit more complicated than a straight 1:7 ratio, you can always refer to our dog age to human years chart to quickly and easily calculate how old your pet is.