Cat Year Calculator:How old is my cat in human years?
Enter your cat's age (or their birthday) and see how old they'd be in human years, using the curve vets actually use. (Spoiler: it's not "multiply by 7".)
Why a curve, not "× 7"?
The old "one cat year equals seven human years" rule is a myth. Cats don't age at a steady rate: they grow up fast, then slow down.
A kitten races to the human equivalent of a 15-year-old by its first birthday, reaches about 24 by its second, and from then on adds roughly 4 human years for each cat year. That's why the line below bends sharply early and then straightens out.
One honest caveat: there's no exact science here. These curves are the rule of thumb vets use to make a pet's life stage relatable. Real aging varies with breed, size and health. Dogs especially: bigger breeds age faster, so the size you pick shifts the curve.
Sources, cat: PetMD / AVMA, Purina, Old Farmer's Almanac. Dog: UC Davis Vet Med, AKC.