Your whole life, you have probably been hearing the mathematical adage about calculating a dog's age as seven years to each of our own.  I know I have.  Well, it turns... out that's not even close to being correct.

According to Britain's Daily Mail, researchers say it boils down to age, size and breed--and their age differs at different stages of the animals life.

For the first three years the figure can be gaged by size.

For small dogs: 12.5 years per human year for the first two years.

For medium sized dogs: 10.5 years per human year for the first two years.

For large dogs: 9 years per human year for the first two years.

Then, for dogs older than three years, the type of breed comes into play.

So .... you would multiply the figure by 13.42 for Bulldog,

7.84 for a larger German Shepherd and

4.32 for a Miniature Dachshund.

Researchers at the University of Georgia also found that dogs that are spayed can live longer lives.

A sample of 40,139 death records showed the average age at death for intact dogs that had not been spayed or neutered-was 7.9 years compared to 9.4 years for sterilized dogs.