All The US Presidents, Ranked By IQ

An intelligence quotient test (IQ test) is a series of standardized tests used to gauge and assess a person's intelligence. While most people will never take a formal IQ test, high IQs have nevertheless always been a topic of public interest.

In recent history, US president IQs have been the subject of debate and discussion. This is in part due to Donald Trump's perpetual tweeting about his high IQ during the controversial election cycle of 2016. This led people to wonder who the smartest and dumbest presidents were throughout history. 

A president's IQ is rarely made public, and many United States presidents were born before the modern IQ test was invented. Nevertheless, many psychological studies have provided educated guesses of presidential IQ based on a variety of factors. 

When it comes to IQ scores, a score over 140 is considered genius level. Research indicates most presidents fall somewhere around 130, but that doesn't mean America has never had a genius in the Oval Office. There are outliers on either side, with many presidents' IQs being higher or lower than average. If you're curious to learn where our presidents rank in terms of intellectual prowess, browse the list below, ranked from highest to lowest.