Dog Age Calculator (in Human Years)

No. The "7-year rule" is a myth. Dogs age much faster in their first two years (about 15 human years in year 1), then the rate depends heavily on breed size. Small dogs age more slowly after year 2, while giant breeds age faster.

Larger dogs age faster than smaller dogs after the first two years. A Great Dane at 8 years old is roughly equivalent to a 72-year-old human, while a Chihuahua at 8 is only about 48 in human years.

The most accurate modern formula uses the natural logarithm: human age ≈ 16 × ln(dog age) + 31, based on a 2019 study of DNA methylation in Labrador Retrievers. However, size-adjusted tables from the AKC remain the most practical approach.

Small and medium dogs are generally considered senior at 7–10 years, large breeds at 6–8 years, and giant breeds at 5–6 years. Senior status correlates with size because larger dogs have shorter lifespans.

No. Cats age differently from dogs. A 1-year-old cat is roughly 15 in human years, a 2-year-old is about 24, and each additional year adds about 4 human years — but the rate is uniform regardless of breed size.