US Presidents’ IQs Ranked From Highest To Lowest

The Dumbest

6. Andrew Johnson

US Presidents' IQs Ranked: Andrew Johnson


Johnson never attended school and was tutored in maths, reading, and writing by his wife. With an estimate of 125.65, he has the fifth-lowest IQ of all the presidents in history. He was the 17th president of the United States from 1865 to 1869. He was the vice president when Abraham Lincoln was assassinated and took over as president shortly thereafter. Therefore, we can say he stumbled upon the presidency.

His lack of grasp on issues can be seen in how he used policy to obstruct political and civil rights for blacks. He believed in the right to slave ownership, an exact opposite conviction held by his predecessor. His racist view and guide almost split America into 2, when the southern state leaders began to call for secession. He found it hard to compromise and faced a lot of challenges in congress. As a result, he lost the democratic nomination ticket to serve an elected term.

7. George W. Bush

US Presidents' IQs Ranked: George W. Bush


His entry into the presidency was just as controversial as his stay. He lost the popular vote to Al Gore, his predecessor’s Vice president but got into the Oval office thanks to the Electoral College. This was a modern wartime president that was a C student with an estimated IQ of 124.8. He served as the 43rd president from 2001 to 2009.

During his tenure, America was hit by the worst disaster in recent history; a terrorist attack at the heart of New York City, The World Trade Center, twin towers. It left about three thousand dead and even more wounded. Bush declared a global war on terrorism and later went into war in Iraq to pursue Weapons of Mass destruction that were never to be found. This decision would lead to the loss of lives of many American servicemen and a general distrust and dislike for America overseas.

Bush despite his low IQ, was funny, always goofed around the podium, and was the most popular president with a 90% approval rating right after 9/11.

8. Warren G. Harding

US Presidents' IQs Ranked: Warren G. Harding


Harding, a Republican, served as the 29th president of the United States from 1921 to 1923 before he died of a heart attack. He had an IQ estimate of 124.3. With such a slow IQ, and coupled with a brief time in service he failed to make any lasting impact. He viewed the presidency as a ceremonial office and he, therefore, avoided issues as much as possible. His lack of leadership and control of his administration saw his government officials get involved in criminal activities.

9. James Monroe

US Presidents' IQs Ranked: James Monroe


Mr. Monroe was the 5th president of the United States. He studied law under Thomas Jefferson. He dealt firmly with the issue of slavery in the new states that joined the Union through the 1820 Missouri Compromise.

He might have been the second dumbest president in US history with an estimated IQ of 124.1. However, he was a very likable character due to his integrity, frankness, jovial personality and a great work ethic. He worked himself to the top and by the time he got to power he was well equipped to handle the pressures that come with it.

10. Ulysses S. Grant

US Presidents' IQs Ranked: Ulysses S. Grant


Grant wins the title as the dumbest president in US history with an estimated IQ of 120. He was the 18th president of the United States with the Republican Party.

Even so, he was an aggressive and determined leader who became a national hero for his efforts in commanding the Union Army during the Civil War. He supported pardons for former Confederate leaders but also worked to protect the civil rights of freed slaves. This pragmatic fluidity made him an effective leader. Perhaps the most interesting fact about him is that he established America’s first national park.