ABC27 WHTM QUESTION OF THE WEEK 12/15

QUESTION OF THE WEEK 12/15

I am a dog lover!  Big time!  I have had one my whole life!  Truth is, I like dogs more than I like most people!  There was my childhood poodle named, Pepe.  Then there was Tucson, a beautiful chocolate lab born with a birth defect.  He only lived 6 years.  I still cry over him!  Since then I've gotten into rescue dogs, my most recent being a chocolate lab/boxer mix named Winston.  He is a love but he's getting old, 12 to be exact.  Of course, in "dog years" you have to multiply that by 7, so he's what, 84?  Holy smokes!  I hope I am as nimble and playful at that age!  But who and how did we come up with that math?  Each human year equals 7 dog years?  Why do we do that?  Why isn't it 6 years or 7 and a half years or let's make it an even 10! 

QUESTION OF THE WEEK:

Where did this calculation for dog age come from?  And why?