Have you ever wondered how your pup’s age converts to human age? For many pet parents, getting the answer to this question is a matter of empathy—as they seek to understand what pups experience at every stage in life.
If you’re looking for answers, you’re in the right place! This article, prepared by Sploot Veterinary Care, sheds light on the controversial question: “What are dog years to human years?”
Read on to learn more about dog age charts and a dog years to human years formula that is backed by recent studies.
Note: We also created a dog years to human years calculator for fast and easy dog age conversions!
Is the 7-Year Rule a Myth or Reality?
For a long time, it has been believed that 1 human year equals 7 dog years. The 1:7 ratio likely comes from prevailing lifespans for both species: dogs live to around 10 while humans typically live to around 70.
But with that said, the 7-year rule is a myth. Here’s why:
1. Dog Years & Human Years are Not Perfectly Linear
A dog’s physical development is rapid during the first years of life. They typically reach full sexual maturity before 2 years of age. If we use the 1:7 ratio for dog years and human years, that would indicate that a 2-year-old dog is only 14 in human years. It is definitely off the mark.
2. Smaller Dogs Tend to Have a Longer Lifespan Than Larger Dogs
The 1:7 ratio of dog years and human years does not take into account that smaller dogs tend to live longer than larger dogs. Furthermore, larger dogs are likely to experience age-related conditions sooner.
How to Convert Dog Years to Human Years More Accurately
Is there a way to convert dog years to human years more accurately? Yes, the two following methods will give more accurate estimates than the 7-year rule:
Method 1: Dog Years to Human Years - Considering Methylation Rates
Regarding the age-old question, “What are dog years in human years?” Molecular biology may have the answer.
A research team led by Tina Wang of the University of California, studied the methylation rates of 105 labrador retrievers. Methylation rates are changes to the DNA related to an organism’s rate of aging.
The resulting formula for dog years to human years uses the ‘natural logarithm’, a mathematical concept often used in determining how fast an organism is aging.
a. The Formula In Action:
The formula, which has been featured in the Smithsonian Magazine and Cell Press is as follows:
- Human years = [(natural logarithm of dog age) x 16] + 31
- To easily get the natural logarithm of a dog’s age, input the number on a natural logarithm calculator or use the ‘ln’ button on a scientific calculator.
Example A: A dog is 2 years old.
- The formula is as follows: [(0.69) x 16] + 31
- The age of the dog in human years is: 42 years old
- Versus the 7-year rule’s answer: 14
Example B: A dog is 5 years old.
- The formula is as follows: [(1.61) x 16] + 31
- The age of the dog in human years is: 56.76 years old
- Versus the 7-year rule’s answer: 35
Example C: A dog is 12 years old.
- The formula is as follows: [(2.48) x 16] + 31
- The age of the dog in human years is: 70.68 years old
- Versus the 7-year rule’s answer: 84
b. Limitations of This Formula
It is important to note that the study involved one dog breed: labrador retrievers. Further study is needed to ascertain if the formula applies to other breeds.
Method 2: Dog Years to Human Years - Using a Dog Age Chart
Another way to easily convert dog years to human years is to use dog age charts provided by credible sources. One example is a dog age chart by Zoetis, an animal health company—the same chart is shared by the American Animal Hospital Association (AAHA).
Dog age charts like the one created by Zoetis indicate the human years equivalent to dog years, based on the size of the dog.
a. The Dog Age Chart in Action
Let’s see how the aforementioned dog age chart compares with the formula based on methylation rates and the 7-year rule:
Example A: A dog is 2 years old.
- Human years based on the above dog age chart: 24 years old (for all dog sizes)
- Versus the answer from the formula that considered DNA methylation rates: 42 years old
- Versus the 7-year rule’s answer: 14 years old
Example B: A dog is 5 years old.
- Human years based on the above dog age chart: 36, 37, 40, or 42 years old (depending on the dog’s size)
- Versus the answer from the formula that considered DNA methylation rates: 56.76 years old
- Versus the 7-year rule’s answer: 35 years old
Example C: A dog is 12 years old.
- Human years based on the above dog age chart: 64, 69, 77, or 93 years old (depending on the dog’s size)
- Versus the answer from the formula that considered DNA methylation rates: 70.68 years old
- Versus the 7-year rule’s answer: 84 years old
b. Limitations of Dog Age Charts:
One key limitation of using dog age charts is that charts tend to have varying information, even if they come from credible sources. This suggests that there is likely no standardized way to prepare these charts.
Dog Years to Human Years Calculator
Convert dog years to human years easily with Sploot's Pet Age calculator. This calculator is based on the pet age chart shared by the American Animal Hospital Association (AAHA).
Note: This dog years to human years calculator is in-page; you will not be redirected.
Final Thoughts on Determining a Pup’s Age & Healthy Aging
To recap, the 7-year rule in determining a dog’s age in human years is a myth. We’ve covered two ways to more accurately convert a pup’s age to human years.
However, as demonstrated in various examples, even these relatively more accurate methods can give different answers.
Moreover, there is currently no formula or dog age chart that can account for individual nuances; routine care, nutrition, lifestyle, and genetics all play a part in the health and longevity of a pup.
For this reason, pet parents are recommended to see their vet regularly. Wellness exams from a trusted vet will yield personalized advice for well-being, help uncover any age-related conditions, and pave the way for happy and healthy dog aging!
For more information on providing great care at every stage of your dog’s life, here are some more comprehensive resources from Sploot:
→ How to Take Care of a New Puppy 101: The 1st Year [Vet-Approved]
→ Routine Dog Care for Health & Well-Being [Vet-Approved Checklist]
→ Caring for Senior or Older Dogs [Vet-Approved]
Veterinary Care for Every Stage in Life at Sploot Vets
Preventive care, which encompasses at-home care and routine veterinary services, is essential for every stage of a pup’s life. Preventive care measures for dogs will change slightly through different stages in their life.
Whatever age your pup may be, Sploot Veterinary Care is a vet clinic that you can count on. We are a primary and urgent care veterinary clinic that addresses over 95% of a dog’s care needs, at every stage in life. From your fur baby’s first puppy exam to adult and senior dog veterinary care, we are always here for you.
Our vet clinics in Chicago and Denver are open 365 days a year, for extended hours. Book an appointment online or through the handy Sploot Vets app. We accept same-day appointments as well as urgent drop-offs.
Till next time, we’re with you every pounce of the way!
Frequently Asked Questions
1. How to calculate dog years?
As mentioned above, dog years were traditionally estimated by multiplying their age by 7, but a better formula is now based on methylation rates: Alternatively, a dog age chart from a reputable source can also give an estimate of your dog’s age in human years.
2. How old is a 14-year-old dog in human years?
Using the methylation formula discussed above, a 14-year-old dog is approximately 73 human years old. Meanwhile, using the dog age chart from the American Animal Hospital Association (AAHA), a 14-year-old dog can be equivalent to the following, depending on the dog’s size: 72 human years (if ≤20 lbs), 78 human years (if 21-50 lbs), 88 human years (if 51-90 lbs), or 108 human years (if >90 lbs).
3. How accurate are dog age estimates?
Dog age estimates on a dog age chart or using the methylation rate formula are close approximations. For a more accurate estimate, visit a trusted veterinarian and/or get their recommendation for a reliable dog age test kit.
4. Is there a test to determine a dog's age?
Yes, vet wellness exams provide age estimates based on physical signs. Meanwhile, DNA tests can further supplement these findings by looking at methylation changes in the dog’s DNA sequence, which correlate to aging.
