How old is my dog in human years?
Not “times seven”: the formula from a 2020 DNA study, and the age when your dog becomes a senior for its size.
Always ask your vet: this site helps you understand, it doesn’t replace a checkup.
Why not “times seven”
Dogs grow up much faster than people in their first two years, then age more slowly. The AVMA itself says the times-seven rule is wrong. A 2020 study on the DNA of 104 Labrador Retrievers found a formula that matches the milestones of both species: human years = 16 × ln(dog’s age) + 31. By that formula, a 1-year-old dog is like a 31-year-old person, and a 12-year-old dog like a 70-year-old.
When does a dog become a senior?
It depends on size: big dogs age sooner. The AVMA says a dog is a senior in the last quarter of its expected life: small dogs (under 20 lb, 9 kg) from 8–11 years, medium (20–50 lb, 9–23 kg) from 8–10, large (50–90 lb, 23–41 kg) from 8–9, giant (over 90 lb, 41 kg) from 6–7. Seniors need a vet checkup at least twice a year.
The formula was found on Labradors: for other breeds and for puppies under one year it’s an estimate.
Sources
- Wang T. et al., “Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome,” Cell Systems 2020 (checked on October 6, 2026)
- AVMA, “Caring for senior cats and dogs” (checked on October 6, 2026)