Dog Years to Human Years: Understanding Your Dog's Age in Their Terms

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two dogs on a bench in the fall

An old adage exists that every year your dog ages is equivalent to seven human years. Thus, a one-year-old dog is roughly the same age as a seven-year-old human, and a ten-year-old dog is roughly equal to a seventy-year-old human. This actually works really well for general terms, but have you ever noticed that bigger dogs seem to age a little faster than little dogs, but how long do these big dogs live exactly? (i.e., eight-year-old Rottweilers seem to “act” older than eight-year-old Miniature Poodles)?  

Beyond 7:1 - Dog Years Get a Scientific Upgrade 

The concept of 'dog years to human years' has evolved with scientific research. The American Veterinary Medical Association suggests that age-related changes in pets, particularly dogs, are influenced by their body mass, breed, and rate of growth. For example, larger breeds age more quickly due to a faster growth rate and generally shorter lifespans. This nuanced understanding goes beyond the simplistic 7:1 age ratio and allows for a more tailored approach to each dog's health and wellness needs. 

The other issue is that even in the same size category, some pets of similar age seem to be older than others – just like in humans, in which we see some 70-year-olds running marathons whereas others have much less stamina at that age. Genetics and DNA (and breed in a dog’s case), lifestyle, diet, and ongoing diseases (such as heart disease, cancer, arthritis, etc.) all factor into the “physiological” age of humans and animals, which is another way of saying how old the body is compared to the number of years we have been alive. 

Recent advances in genetic research have provided new insights into the aging process of dogs. Scientists involved in projects like the Dog Aging Project have used biomarkers such as DNA methylation to develop more accurate methods for calculating the age of dogs in human years. This research supports the idea that dogs mature rapidly in their early years, but the rate of aging is significantly influenced by the size and breed of the dog. 

A Quick Dog to Human Years Age Chart 

Here’s a quick chart to help you estimate your dog’s age in human years. However, these figures are general approximations and not precise calculations. Precise conversions are impossible due to factors like breed, individual health, size, and genetics. For a clearer picture of your dog's true age, consult your veterinarian. They'll consider your furry friend's unique characteristics and health story to paint a far more accurate picture of their well-being. 


Small (<20 lbs) 

Medium (20-50 lbs) 

Large (>50 lbs) 

Puppy (1 year) 

15 human years 

15 human years 

15 human years 

Young Adult (2-3 years) 

24-28 human years 

24-28 human years 

24-28 human years 

Adult (5 years) 

36 human years 

37 human years 

40 human years 

Senior (8 years) 

56 human years 

51 human years 

55 human years 

Geriatric (12 years) 

64+ human years 

64+ human years 

77+ human years 

Puppies and Developmental Milestones: Comparing Canine and Human Growth 

Animals in general tend to develop much faster than humans because, instinctively, they must be ready to survive in the wild. A lot of what a puppy can do at the equivalent age of a human is going to be a bit more advanced. For example, puppies can crawl almost immediately after birth. As far as brain development goes, humans may take a little longer to develop, but we tend to be able to learn, retain, and understand much more than a dog ever will. Between physical and brain development, estimating equivalent ages between humans and puppies is a little tricky.  

Compare some of the common development milestones below: 


  • Puppies: 0-3 days 

  • Humans: Around 6 months 


  • Puppies: 5-7 days 

  • Humans: Around 1 year 


  • Puppies: 4-6 weeks 

  • Humans: Often much later (typically 6 months-2 years) 

Understanding or recognizing words 

  • Puppies: 8 weeks 

  • Humans: 6-12 months 

Following simple directions 

  • Puppies: 8 weeks 

  • Humans: 9-12 months 

Potty training 

  • Puppies: 6-16 weeks 

  • Humans: 2-3 years 

Growth plate closures 

  • Puppies: By 18 months-2 years 

  • Humans: By 14-16 years 

*These are averages at best and meant to be used for comparison purposes. 

So where does that leave us? Averaged together for both brain and body development, a two-month-old puppy is probably about the same age as a one-year-old human. At one month, he is probably closer to a six-month-old human. At four months old, he is probably roughly the same age as a two or three-year-old human. This will depend a little bit on the breed and size of the dog. Some dog breeds develop more slowly than others (physically, mentally, or both), but just like with humans, everybody pretty much catches up to each other eventually. After about six months of age, puppies slow down in their growth and development. They reach canine puberty at six months to one year of age, so a one-year-old dog is roughly the equivalent of a twelve-year-old human physically, with similar stamina, energy, and emotional maturity. Dogs will typically have reached their full size at around 18 months to 2 years of age. This is similar to around a 15-year-old human, give or take several years. 

Adult Dogs and Aging: Understanding the Variation 

As you can see, aging varies a bit with young dogs, not quite following the “seven year” rule. Estimating age gets a little less complicated with adult dogs, other than accounting for breed and size. Historically, larger breed dogs and larger-framed dogs live an average of 10 years, whereas smaller breed dogs and smaller-framed dogs live an average of 14 years. 

This rather large difference in aging among sizes and dog breeds has been studied by many scientists. The major reason found is that larger dogs literally age faster than smaller dogs. One study went so far as to say that for every 4.4 pounds of body weight a dog has, his life expectancy is decreased by 1 month.

Essentially, because big dogs age faster, this means that a 10-year-old large dog is the same physiological age as a 14-year-old small dog. 

Now consider the average life expectancy of a human, which is around 80 years of age. The 10 year old large dog and the 14 year old small dog are essentially both 80 year olds in human years. After a little mathematics, we can estimate rough ages for the different size categories: for every year of age into adulthood, a larger dog ages about eight years in human years, and a smaller dog ages roughly six years. Thus, an otherwise healthy six-year-old Labrador Retriever would be the equivalent of a forty eight-year-old human, and an otherwise healthy six-year-old Yorkshire Terrier would be the equivalent of a thirty six-year-old human. This doesn’t quite match up with the “seven year” rule, but it’s pretty close.  

The AVMA’s Take on Dog Years Vs. Human Years 

As our beloved canine companions enter their golden years, it's important to recognize when they are transitioning into the senior phase of life. The American Veterinary Medical Association (AVMA) provides guidelines that help pet parents identify this life stage, which varies significantly among dogs due to differences in breed and size.  

According to the AVMA, a dog is generally considered "senior" in the last 25 percent of their expected lifespan, a milestone that is reached at different ages for different sizes of dogs:  

  • Small or Toy Breeds (<20 pounds): These petite pups are typically seen as seniors at ages ranging from 8 to 11 years. Their smaller size often allows them a longer life expectancy, and they tend to enter their senior years later than their larger counterparts. 

  • Medium-Sized Breeds (20-50 pounds): Medium-sized dogs are usually classified as senior between 8 to 10 years of age. This category covers a wide range of breeds, often characterized by a balanced life expectancy that is reflective of their moderate size. 

  • Large Breeds (50-90 pounds): Larger breeds age faster and are considered senior between 8 to 9 years. Their size correlates with a more accelerated aging process, and they may require earlier intervention to manage age-related health issues. 

  • Giant Breeds (>90 pounds): The gentle giants of the dog world, such as Great Danes and Mastiffs, typically become seniors earlier, around 6 to 7 years. Due to their considerable size, giant breeds have a shorter average lifespan and may show signs of aging sooner. 

Age is Just a Number 

Estimating human age is just that, an estimate. Nowadays, all dogs, both mixed breeds and pure breeds, are living longer because of the advances in veterinary medicine. Equally important, pet owners are making better efforts to keep their pets healthy with diet, exercise, and overall care. As a veterinarian, I know many 15-year-old large dogs, and they certainly don’t act like they are 120-year-old humans!  

The most important point is, regardless of how old you, your vet, or your dog thinks or feels he is, age is just a number. With improvements in veterinary care and pet owner education, dogs are enjoying longer and healthier lives. While there are no guarantees, doing whatever you can to keep your pet healthy and happy is the ultimate key to their longevity. 

Pet Insurance: A Smart Choice in Understanding Your Dog's Aging Process 

While figuring out your pup's age in human years might spark fun conversations, it doesn't guarantee a healthy future. Pet Insurance helps you navigate the path to a healthy, vibrant life for your pup, from playful moments to wise old cuddles. That's why Embrace offers comprehensive coverage to navigate life's unexpected moments, from common illnesses and accidents to chronic conditions. 

Enrolling your pup early helps avoid pre-existing conditions that could limit future coverage, so you can rest assured knowing they're protected down the road. But we don't stop there. Our flexible plans cover a wide range of accidents, illnesses, and conditions, from wobbly knees to unexpected surgeries, ensuring your furry friend receives the best care when they need it most. 

As your dog enters their senior years, the question "how old is my dog in dog years?" becomes more important than human years. And with Embrace by your side, you can watch your pup age gracefully, free from the financial worry of unexpected health concerns.  

Deciphering Dog Years: Beyond the Calculator 

While the "7 dog years to 1 human year" adage holds a certain charm, understanding your furry friend's true age story demands a deeper dive. Science reveals a nuanced picture, where breed, size, and individual characteristics significantly influence the canine aging process. This knowledge empowers you to provide tailored care, celebrate milestones with greater awareness, and navigate your dog's unique journey with confidence. 

Age, though just a number, becomes a valuable compass. It guides you in understanding your dog's physical and cognitive development, anticipating their needs, and offering optimal support at every stage. The playful puppy exploring the world is a canine in the throes of rapid neural development and physical growth. Similarly, the senior dog dozing by the fire is a seasoned canine companion whose needs and pace deserve sensitive consideration. 

Embracing this nuanced understanding unlocks a deeper connection with your dog. Each playful bark, each gentle lick, each wet-nosed nudge builds a lasting bond that transcends time. Forget the limitations of arithmetic; focus instead on the boundless joy of companionship, the profound wisdom in those soulful eyes, and the unconditional love that transcends the ticking clock.