Pet Year Calculator:How old is my pet in human years?
Enter your pet's age (or their birthday), then pick cat or dog to see how old they'd be in human years, on the curve vets actually use. (Spoiler: it's not "multiply by 7".)
Why a curve, not "× 7"?
The old "one pet year equals seven human years" rule is a myth. Cats and dogs don't age at a steady rate: they grow up fast, then slow down (and bigger dogs age faster).
A kitten or puppy hits the human equivalent of a 15-year-old by its first birthday and about 24 by its second, then adds roughly 4 human years a year (more for big dogs). Pick cat or dog above to match the curve.
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.