Pet Age Calculator: How to Convert Dog and Cat Years to Human Years

The old rule that one dog year equals seven human years is a myth. Modern veterinary science shows that dogs age faster in their early years and then slow down, with size being a major factor.

A 1-year-old dog is roughly equivalent to a 15-year-old human. By age 2, they're about 24 in human years. After that, each additional year adds about 4-5 human years — but smaller dogs age slower than larger breeds.

Cats follow a similar pattern: the first year equals about 15 human years, the second adds 9 more years (age 24), and each subsequent cat year equals about 4 human years.

Our Pet Age Calculator at Age Right Now uses the latest veterinary guidelines with separate formulas for dogs (by size: small, medium, large, giant) and cats.

Try it to find out your pet's real human-equivalent age — it's more accurate than the old 7-year rule and accounts for breed and size differences.