Estimates online suggest that GWB has an IQ of 120-125, making him smarter than the average college grad, perhaps slightly less intelligent than the average person with an advanced degree.

It's also worth noting that IQ is not a particularly good predictor of presidential success, and only a partial measure of intelligence.

https://en.m.wikipedia.org/wiki/U.S._Presidential_IQ_hoax#ci...

http://www.assessmentpsychology.com/