Pet Age Calculator
Turn your dog or cat's age into human years using the modern, non-linear method.
Note on the numbers: the per-year aging rates used here (about 4 human years/year for small dogs and cats, up to 7 for giant breeds) are approximate constants from a widely cited method and vary by breed, genetics, and individual health. Treat every result as an estimate and verify anything health-related with your veterinarian.
Frequently asked questions
Why shouldn't I just multiply my pet's age by 7?
The "one dog year equals seven human years" rule is a myth. Pets mature very quickly in their first two years - a one-year-old dog or cat is roughly a 15-year-old human - and then age more slowly at a rate that depends on species and, for dogs, body size. This tool uses that non-linear pattern instead of a flat multiplier.
How does this calculator work out the human-equivalent age?
It uses a widely cited size-adjusted piecewise method: the first year counts as about 15 human years, the second year adds about 9 more (so 2 pet years is about 24 human years), and each year after that adds roughly 4 (small dogs and cats) up to 7 (giant dog breeds) human years. Larger dogs age faster, so they reach each life stage sooner.
Is the result exact?
No. It is an approximation based on average aging patterns. Real biological age depends on breed, genetics, diet, and health, so treat the number as a friendly estimate and consult your veterinarian for anything health-related.