Dean Simonton, a researcher from the University of California at Davis, created a system to estimate presidential IQs. He based each score off of the leader’s intellectual brilliance and openness. On average, most of the presidential IQs fall somewhere around 130. However, some IQ scores fall below that average. And some are higher than the average. Here are the former presidents ranked by IQ:
The Highest Presidential IQs
John Quincy Adams
IQ score: 168.75.
John Quincy Adams is technically the smartest president in the country. He studied law at Harvard University. Adams served as president from 1825 to 1829. He is famous for ending the War of 1812 and settling the Treaty of Ghent.
IQ score: 153.75
Thomas Jefferson was a lawyer and politician. He was the third president in office and worked in the White House from 1801 to 1809. He is famous for writing the Declaration of Independence in his thirties.
John F. Kennedy
IQ score: 150.65
John F. Kennedy studied at Harvard, then served with distinction in the Naval Reserve in World War II. He was the American president during the Cold War. He also served throughout the rising civil rights and women’s equality movements.
IQ score: 148.8
Bill Clinton had a lot of family drama while he was in office. However, he was one of the smartest leaders in terms of his IQ. Before becoming president, he started out teaching law. Then he moved on to becoming Arkansas’ governor. Finally, he became president in 1993.
IQ score: 145.1
Woodrow Wilson opened a law firm, then went back to college for political science. He was elected as President of the United States in 1913. He was the twenty-eighth American president.
IQ score: 145.1
Before becoming president, Jimmy Carter studied agriculture and accounting. He served as governor of Georgia in 1971. Then he moved on to become the 39th president of America. However, he was voted out after one term.
IQ score: 142.5
John Adams was a lawyer and political theorist. He was the second president in the U.S. His presidency lasted from 1797 to 1801.
IQ score: 142.28
Theodore Roosevelt was the youngest man to hold presidential office. He was originally vice president. He took over when President William McKinley was assassinated. Roosevelt went on to win the Nobel Peace Prize in 1906.
IQ score: 141.5
James Garfield served one of the shortest terms in the country’s history. He was President of the United States in 1881. However, he was shot only six months after he took office.
IQ score: 141.5
Chester Arthur was the vice president for Garfield. However, he took over after the man’s death, becoming the 21st president. He served as President of the United States from 1881 to 1885.
IQ score: 141.25
James Madison served two terms as president. He is known as the Father of the Constitution. He drafted the U.S. Constitution and the Bill of Rights.
IQ score: 140
Lincoln decided to get into politics after his business failed. He was outspoken about slavery because he believed that everyone should be equal, as the Founding Fathers have stated. Lincoln is most famous for signing the Emancipation Proclamation that ended slavery.
IQ score: 139.6
Roosevelt was the only one of the U.S. presidents to serve three terms. He took office during the Great Depression, declared war on Japan after Pearl Harbor, and created the Social Security program we use today.
IQ score: 136.2
John Tyler started out as a lawyer. His clients helped him enter the world of politics. Then, when William Henry Harrison died, John Tyler became president. He was the first vice president to become president without an election.
IQ score: 135.98
Before becoming president, Millard Fillmore was a lawyer. He went on to run as vice president with Zachary Taylor. When Taylor died, he took over as president from 1850 to 1853.
More Presidential IQs
IQ score: 134.78
Franklin Pierce is regarded as one of the worst presidents in history. He created the Kansas-Nebraska Act. This allowed new territories to decide for themselves whether to allow slavery.
William Henry Harrison
IQ score: 133.93
William Henry Harrison entered politics after success in the military. He was the first governor of Indiana and the country’s ninth president.
Rutherford B. Hayes
IQ score: 133.93
Rutherford B. Hayes worked in a law office before becoming the 19th president of America. He defended runaway slaves and promoted civil service reform.
Martin Van Buren
IQ score: 133.35
Martin Van Buren was the eighth president. He was a member of the Democratic Party, but he was considered a poor president. He was called Martin Van Ruin by some because he created a weak economy.
IQ score: 132.5
George Washington was the first president in the country. His family’s poverty forced him out of school, and he spent time in the military. He became president in 1789 and stayed in the White House until 1797.
IQ score: 132.15
Harrison was the 23rd president of the United States of America. He started as a lawyer and church leader. Then he was elected as president in 1889.
IQ score: 131.9
Dwight Eisenhower was America’s 34th president. He served as the first Supreme Commander of NATO. He also expanded social security.
IQ score: 131
Nixon went to college to study law. He also served in World War II. Unfortunately, he’s the most famous for being the only president to resign from office.
IQ score: 130.95
Grover Cleveland passed the bar exam, even though he couldn’t afford to attend college. He became the governor of New York, then moved on to becoming president for a single term. However, he returned to the White House four years after leaving.
James K. Polk
IQ score: 130.2
James K. Polk was the 11th president. He extended America’s borders and helped them become a world power. Unfortunately, he died three months after leaving the White House.
IQ score: 130.18
William McKinely was the 25th president of the U.S. He started and won the Spanish-American War. He also gained Puerto Rico, Guam and the Philippines from Spain. Unfortunately, his presidency ended in an assassination.
George H.W. Bush
IQ score: 130.13
George H.W. Bush was ambassador to the United Nations. He also served in Congress and was chairman of the Republican National Committee. He was president when the Berlin Wall fell and the Soviet Union was dissolved.
IQ score: 130
Ronald Reagan was originally an actor. He went on to serve two terms as governor of California. However, he ran for president three times before winning the election.
IQ score: 129.78
Herbert Hoover was a successful businessman. However, he struggled as president during the Great Depression. He worked in an advisory capacity for over three presidential terms.
Lyndon B. Johnson
IQ score: 127.83
Lyndon B. Johnson became president after John F. Kennedy was assassinated. He was officially sworn into the White House as president in 1963. He improved civil rights, but he was criticized for how he handled the Vietnam war.
IQ score: 127.55
Truman never earned a college degree. He was blind in one eye, so he cheated on a vision test to enter the military. Then he became president in 1945. He developed the United Nations, developed NATO, and prioritized civil rights.
IQ score: 127.1
Calvin Coolidge was the 30th president of the United States. He served from 1923-1929. He was called Silent Cal by many because his actions spoke louder than his words.
The Lowest Presidential IQs
IQ score: 127.08
Gerald Ford studied law in school while working as an assistant football coach. He was vice president and became president when Richard Nixon quit. Although he inherited high inflation and rising unemployment, he supported equal rights.
William Howard Taft
IQ score: 126.9
William Howard Taft finished second in law school. He worked as a lawyer, a judge, and the U.S. secretary of war. He only served one term as the nation’s president.
IQ score: 126.25
Jackson is remembered for his support of slavery. He was a slave-owning plantation farmer who got into politics after military successes. However, he is the only U.S president to completely pay off the national debt.
IQ score: 125.93
James Buchanan was originally a member of the Federalist party. Then he switched to the Democratic party. Historians view him as one of the worst presidents because he overlooked slavery. He brought the country to a Civil War.
IQ score: 125.65
Tyler was only in the White House for sixteen months before his death. He was elected as President of the United States based on his military successes.
IQ score: 125.65
After Lincoln was assassinated, Andrew Johnson became president. Many believe he is one of the worst men to work in the White House. Freed slaves lost a lot of civil liberties after he allowed Southern states to form their own civil governments.
George W. Bush
IQ score: 124.88
Bush was a controversial president. Some people weren’t happy with the way he handled the Iraq war and the response to Hurricane Katrina.
Warren G. Harding
IQ score: 124.3
Harding helped the economy turn around after World War I. Unfortunately, he died of a heart attack. It was later exposed that his cabinet members were corrupt.
IQ score: 124.13
Although James Monroe has a low IQ score, it doesn’t mean he wasn’t intelligent. He extended America’s borders and supported founding colonies in Africa for freed slaves.
Ulysses S. Grant
IQ Score: 120
Ulysses S. Grant was uninterested in school. He served with distinction in the Army, then was a general in the Civil War. However, as a president, he couldn’t stop the depression in the 1800s.