In "progris riport 5-Mar 6," Charlie writes that he has an "eye-q" or I.Q. of 68 (page 9). At this point, Dr. Nemur is worried that Charlie will get sick from having an I.Q. that climbs too high following his operation. In Progress Report 12, Charlie writes, "I'm just as far away from Alice with an I.Q. of 185 as I was when I had an I.Q. of 70" (page 116). This means that his I.Q. has almost tripled since his operation. It should be noted that I.Q. is now a very controversial way to measure intelligence. According to the I.Q. test, people with an I.Q. under 70 are generally known as having "very low" intelligence, while those having an I.Q. over 130 are known as having a "very superior" I.Q. People like Marilyn Vos Savant, who was measured in the Guinness Book of World Records as having the highest I.Q. measured to date (190 in the 1980s), have I.Q.s in line with that of Charlie after his operation. Of course, as Charlie realizes, having a high I.Q. does not mean that he is easily able to have a good relationship with Alice.
Before his operation, Charlie's IQ is around 70. However, following his operation, his IQ begins to rise, as reflected by his word choice, punctuation, and sentence structure.
In the entry for April 16, Burt Seldon tells Charlie that his IQ is around 100, but that soon it should rise to above 150.
On June 6, Alice and Charlie get into a fight. He sadly realizes that it is in part because their levels of intelligence are just as far apart as when the experiment started, but now he is the more intelligent one, with an IQ of 185. This is the highest clearly indicated point of Charlie's IQ, although it's possible that his IQ continued to rise and that he simply did not take the time to measure it.