Enter your dog age in years and see roughly how old they would be in human terms. The old rule of multiplying by seven is a myth, because dogs mature very quickly in their first two years and then age more gradually after that. This calculator uses a more realistic approach: the first year of a dog life counts for about fifteen human years, the second adds around nine more, and each year after that adds roughly four to five human years depending on the dog size, since smaller breeds tend to live longer than larger ones. Pick your dog size for a closer estimate. It is a fun and useful way to understand your companion life stage. Everything runs locally in your browser with nothing stored.