As of October 23, 2014, AR12192 is now the Biggest sunspot in 2 solar cycles. Just yesterday it reached the rank of largest sunspot in cycle 24.
The sunspot measures a whopping 2700 microhemispheres (MH or millionths of a visible solar hemisphere). Now it has surpassed AR10486 (2610 MH) of the famous 2003 Halloween storms. It is the largest sunspot since AR6368, which measured 3080 MH on November 18, 1990.
AR12192 is the largest in almost 24 years!
A reminder for scale, the surface area of Earth is 169 MH.