Free interactive tool
Pet age → human years.
Modern research shows the old "1 dog year = 7 human years" is a myth. Our calculator adjusts for species, breed size and life stage.
Species
Size
Age3y 0m
3 years
0 months
Estimated human age
29
human years
Life stage
Adult
Feeding: 2 measured meals per day; adjust by body condition.
Vet visits: Once yearly, keeping vaccines current.
The science
Why not 7 to 1?
A 2019 UC San Diego study used DNA methylation (an epigenetic clock) to show dogs age extremely fast in their first two years — approximately 30 human years' worth. After that, aging slows and correlates strongly with breed size. Small dogs live longer than giants. Cats age similarly quickly early on, then plateau.
Our calculator blends these findings into a simple estimator — a starting point for you and your vet, not a diagnosis.