The Real Way to Calculate Your Dog’s Age in Human Years
When it comes to calculating a dog’s age, most go by the well-known formula that "one dog year equals seven human years" – however the truth is, this isn’t accurate.
It's not as simple as a one-size fits all model – as the breed of a dog very much comes into play.
Large-breed puppies tend to mature more slowly than small and medium dogs. But, when they hit adulthood, these larger breeds often age faster than the average dog.
This means larger breeds, like Great Danes, can be pensioners (by human standards) at 6 or 7 dog years. Whereas a Jack Russell Terrier, on the other hand, would typically be considered a senior citizen around the age of 10-12.
It's also worth pointing out that, just like humans, a dog’s lifespan depends on numerous factors, including diet, healthcare and activity level – to name a few. But if you want to work how old your dog is in human years, keep reading...
How to calculate dog years to human years
According to the the Kennel Club, the general guidelines for determining how old a dog is are the following:
The first two years of a small dog’s life is roughly the same as 12.5 human years, while it’s 10.5 for a medium dog and nine for large dogs.
Each additional year of the dog’s life is then multiplied by between 4.3 and 13.4 years, depending on the breed, to find their human age.
The stages of a dog’s life
According to the American Animal Hospital Association, there are five age-related stages in the life of a dog:
Puppy: Birth to 6-9 months (the end of rapid growth); depends on breed and size
Young Adult: 6-9 months to 3-4 years (the completion of physical and social maturation)
Mature Adult: 3-4 years to beginning of the last 25% of estimated life span; depends on breed and size
Senior: Last 25% of estimated life span to end-of-life
End-of-life: The terminal stage
The 1 human year to 7 dog years myth
It’s unclear where the "1 human year to 7 dog years" myth originated. However, the earliest known reference dates back to a 1268 inscription in the floor of Westminster Abbey – which calculated the date of Judgment Day using the life spans of various creatures, including dogs and people.
Numerous recent scientific studies, including The Dog Ageing Project, have debunked this myth and have shed light how our canine friends actually age.
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