The common formula stating that “one year equals seven dog years” is a myth without any scientific evidence to back it up. A new theory suggests that chemical alterations to someone’s DNA throughout their life create what is known as an epigenetic clock. Dogs and wolves have also been shown to go through these DNA changes. Scientists used the Labrador Retriever to find the scientifically correct formula to convert to dog years to human years. The dog’s age is multiplied by 16, plus 31.
Source: https://www.sciencemag.org