SUMMARY: A nice graphic.
There's no true correspondence between a dog's age and a human's age, and certainly not a linear one like "one dog year is equal to 7 human years"--for example, a dog could have puppies at 6 months, and that old adage would make it age 3.5 for humans. Huh-uh. And so much depends on both the breed and the dog's size.
This is a nice one; don't know what data went into it, but it looks to me like a decent approximator.
(Per copyright on image, from Dog Owner's Manual--used with permission--although found on this site.)
According to this, Tika is around 80 (mighty dang spry for an 80-year-old, I'd say--but certainly as hard of hearing as, say, my dad around that age), and Boost and I are about the same age. Yay, us.
