What is the equivalent of dog years to human years?

Though we spend so much time together, dogs and humans age differently. You might be familiar with the concept that dog years to human years is a 7:1 ratio. If you multiply your pup’s age by seven, the result is their age in “dog years.” But this ratio isn’t quite accurate. 

In a recent study, the UCSD School of Medicine compared dog years to human years. The results prove that the 7-year method doesn’t work. In reality, it’s a more complex formula to equate dog years to human years. 

Dogs age most rapidly in their first year of life. Though it’s only one year for us, it’s about 15 in dog years. This means your dog is going through infancy, childhood, and adolescence in the span of 12 months. No wonder the puppy stage is so difficult! 

The aging process slows a bit in year two. Your pup will age around 9 dog years in this time frame. From year three onwards, dogs age about 4 to 5 dog years per human year. 

Of course, this formula isn’t accurate for every dog. Some pups may age faster or slower depending on their breed, size, activity level, or gender. 

Dog Age Chart

The dog age chart below follows the UCSD formula. It breaks out how our dogs age based on their size grouping. If you prefer to do the math yourself, the formula is (human_age = 16ln(dog_age) + 31).

You’ll notice that dogs age about the same in their first 5 years, regardless of size. But in the fifth year, large dogs begin aging faster than small and medium breeds. Small dogs are the most versatile and only age about 4 years at a time from this point on. 

How Size Impacts Dog Lifespan

Curious why large breed dogs age more rapidly? It seems contradictory to the rules of the animal kingdom. Typically, the larger the animal, the longer they live. 

Elephants, for example, live about 40 to 75 years. Smaller mammals, such as mice or rats, only live about 12 months. Dogs are the exception to this rule. 

Most puppies are born a similar size regardless of breed. But large breed puppies need more energy and calories to grow to their adult size. That’s one reason large breed puppies need a more complex diet – they are burning so much energy just to get bigger. 

This means large breed dogs may experience more “genetic wear-and-tear” than small and medium dogs. At a certain age, large dogs may be more susceptible to cancer and illness. 

Just because you have a large dog doesn’t guarantee a short lifespan. But parents of larger breeds should pay close attention to their dog’s wellness. Prioritize regular vet visits, a healthy diet, daily exercise, and mental stimulation. 

Female vs. Male Dog Lifespan 

Did you know that women tend to live longer than men? Funny enough, the same goes for dogs. 

One study found that the male dog lifespan is shorter than that of females. The average female dog lifespan is 11.41 years. Male dog lifespan is slightly less at 11.07 years. 

Male versus female dog lifespan is also dependent on spaying and neutering. The same study found that spayed dogs live longer than unspayed females. Similarly, male dog lifespan is longer for neutered dogs.  

What breeds have the longest dog lifespan?

Breed also plays into how our dogs age. For example, Jack Russell Terriers live an average of 13 years. French Bulldogs, on the other hand, have an average lifespan of 4.5 years. 

Brachycephalic dog breeds tend to have the shortest lifespan. Pugs, Bulldogs, and other breeds in this category have flat faces, making it difficult for them to breathe. These same breeds also face an increased likelihood of skin fold infections and spinal disease. 

Curious which breed has the longest dog lifespan? Surprisingly enough, Chihuahuas take the crown. These tiny but mighty pups have an average lifespan of 15 years. Some Chihuahuas can live up to 18 or 20 years. 

Make Every Dog Year Count

Since dog years pass so quickly, it’s important to make every day count. You might be lucky enough to have multiple dogs in your lifetime. But you’re likely the only human parent your dog is going to have in theirs. 

Take advantage of the time you have with your pup. You can make every day count by setting the perfect daily routine. 

Start and end the day with a bowl of quality dog food. Sundays for Dogs offers complete and balanced nutrition for dogs of all size, breed, and background. Made with only 100% human-grade ingredients, Sundays provides your pup with the nutrients they need to be healthy and happy every day. 

Set aside time each day to focus on your dog’s needs. This time might be best spent throwing the ball, brushing their coat, or loafing on the couch in a cuddle session. It doesn’t have to be long – even just 10 minutes of dedicated bonding time can be good for both you and your dog. 

Try to walk your dog every day. Dogs need exercise and mental stimulation to be their best selves. A walk around the neighborhood provides both! Let your furry friend discover new scents while getting a few steps in. 

Say “I love you” at least once a day (if not more). You and your dog might not speak the same language, but that doesn’t mean you can’t communicate. One study shows that dog’s have a positive physiological response to “I love you.” Whether you say it once, twice, or a hundred times a day, this means something to your pup.