If you’ve ever owned a dog, you know that your dog has two “ages” — their actual age, and their age in so-called “dog years.” To calculate dog years, you simply multiply the dog’s age by seven. But is there any actual scientific evidence behind this formula?
The short answer is no — but scientists have come with a more accurate way to calculate it.
Researchers at the University of California, San Diego, examined dog DNA to see how quickly dogs age. They looked at 104 Labrador retrievers from 1 month to 16 years old, comparing their rates of DNA methylation – which usually speeds up as living beings age – to those of humans.
The researchers found that the rates of methylation were similar between dogs and humans; however, adolescent and mature dogs experienced more accelerated aging.
Based on this data, they came up with a new formula for calculating dog years.
Take the natural logarithm of a dog’s age, multiply it by 16, and then add 31.
By this measure, a 2-year-old dog would be 42 human years old – way older than 14!
However, methylation slows later in life, so the dog’s age in human years doesn’t increase as quickly. A 5-year-old dog would only be 57 years old, while a 6-year-old dog would be 60. A 10-year-old dog would equate to a 70-year-old human.
This formula might not be completely accurate for every dog breed, as different dogs age at different rates, while the formula was determined based on data from Labs. Still, it’s a very interesting and informative contrast to the old unscientific 7-year rule!