Wasn't this first reported by John Gruber @ Daring Fireball?
I've been saying a 7.85" iPad Mini is an equivalent to a ~8.1-2" Android tablet for a while on this forum
It's pretty interesting phenomenon how so many people put an emphasis on the first number of a diagonal, while completely ignoring the ".85" part as well as the aspect ratio, both affect the size significantly.
Then again, it's probably related to why we see a product priced "999.99" instead of "1000" all the time.