Most of us have heard certain equations for converting our favorite animal’s age to an equivalent human age. These equations have mostly been linear conversions with the most popular stating that every human year is equal to seven years for your dog or cat. As it turns out it isn’t that simple, and dogs, cats, and humans all age at different rates.
The biggest problem with these equations comes in the first year when smaller animals like cats and dogs develop significantly more quickly than humans would even when accounting for their shorter life span. The original seven-year rule would have you think a one-year-old cat or dog is equal to a 7-year-old human. In reality, a one-year-old dog is equivalent to a 31-year-old human whereas a one-year-old cat is equivalent to a 16.6-year-old human. Surprisingly, the old seven-year rule is not too far off as the dog aging process slows down as they get older and gets closer to the original seven-year rule result. The original seven-year rule has been around since the 1950s and the new formulas have only come recently from new studies.
True cat age was found in a study published in 2017 by iMedPub Journals, while true dog age was discovered in a study published in 2020 by Cell Systems. Unfortunately, these equations aren’t as simple as the seven-year rule with the new equation for cat age being
human age equivalent = 16.6364
when your cat is 1-year-old and
human age equivalent = (4.1364*cat age)+15
when your cat is 1.5 years and older. The new equation for dogs is
human age equivalent = 16ln(dog age) + 31
with the ln being “natural log” and should be featured in your phone’s calculator.
These types of studies aren’t simply a debunk of the seven-year rule or an accurate way to tell your favorite pet’s human age equivalent. These studies reveal some interesting facts when you talk about the oldest cat or dog. The oldest cat ever lived to 34, which is 155.64 in cat years, and the oldest dog lived to 29 years and 5 months, equivalent to 85 in dog years. The dog study reflects our recent advances in genetic technology. The dog study helps us establish a new epigenetic clock for dog cells to determine how old they are and helps vets guide their treatment and recommendations. These new studies also mark a jump in our understanding of how different species age. These types of discoveries bring us a step closer to understanding the underlying reasons for aging, which could eventually help us slow aging in humans.
George Zell is a Marketing Intern at the Connecticut Science center where he produces and posts for some of the online content platforms. He is currently a senior working to get his Bachelors of Science in Business Marketing from the University of Hartford.