In human years, that’s about
How old is my dog or cat in human years?
The old “one dog year equals seven human years” rule is a myth. Pets grow up fast in their first two years, then age more slowly — and dogs age at different rates depending on their size, with giant breeds ageing the quickest. This calculator uses the modern, size-aware approach vets favour to estimate your pet’s age in human years.
This is a friendly estimate, not veterinary advice. Ageing varies with breed, genetics and health — for anything about your pet’s wellbeing, ask your vet.
Frequently Asked Questions
Is one dog year really seven human years?
No — that’s an old oversimplification. A dog reaches roughly 15 human years by age one and about 24 by age two, then adds four to seven human years per calendar year depending on its size.
Why do bigger dogs age faster?
Large and giant breeds mature and grow old more quickly than small dogs, so each later year counts for more human years. That’s why a giant breed of eight can be “older” than a small breed of the same age.
How do you calculate a cat’s age?
Cats reach about 15 human years by age one and 24 by age two, then roughly four human years for every year after — similar to a small dog.
When is my pet a senior?
Most cats and small dogs are seniors around 10–12, medium and large dogs around 8–10, and giant breeds as early as 6–7. Ask your vet about senior wellness checks.