U.S. scientists say calculating \"dog years\" by multiplying the pup\'s age by seven is misleading depending on the animal\'s breed and size. Dog owners can more accurately pin down their pet\'s age relative to a human\'s by taking into account what specific kind of dog they own and where they are in the developmental process, The Daily Telegraph said Friday. Larger dogs tend to live shorter lives than smaller dogs, but smaller dogs mature faster. In other words, a small dog like a chihuahua is technically \"older\" than a pit bull for the first several years but as they advance, the chihuahua\'s aging process slows relative to the larger pit bull in relation to the animals\' average life span. Kate Creevy, assistant professor of internal medicine at the University of Georgia, said when the average of all this information is taken into account, dogs age at about six years in a calendar year, not seven. Creevy was quick to note, however, that the six year figure can vary widely by breed.