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See your equivalent biological age, generations passed & classic 7× scale
Convert from any animal to human age, or directly compare two different species (e.g. Dog to Cat, or Parrot to Hamster!).
The "rule of seven" is one of the world's most famous pet myths, but here is what veterinary biology and genetics actually tell us.
In the mid-20th century, the average human lifespan was around 70 years, and the average dog lived about 10 years. People simply divided 70 by 10 to get 7. It was an easy marketing rule for veterinarians to encourage annual checkups, but it ignored biological development entirely.
In 2020, researchers at UC San Diego analyzed DNA methylation patterns across human and dog genomes. They discovered that dogs age exceptionally fast during their first 2 years, reaching full sexual maturity, before their biological clock slows down significantly.
Human Age ≈ 16 × ln(Dog Age) + 31
Under this curve, a 1-year-old dog is biologically ~31 human years old, a 4-year-old dog is ~53, and a 12-year-old dog is ~71!
Unlike in most of the animal kingdom (where giant whales and elephants outlive mice by decades), large dog breeds (like Great Danes) age much faster and have shorter lifespans (~7–8 years) than tiny breeds like Chihuahuas (~15–18 years). Their rapid early cellular growth causes higher oxidative damage.
Cats age roughly 15 human years in their first year, reach young adulthood (~24 human years) by age 2, and then add about 4 human years for every calendar year thereafter.