Bill Gates's IQ: What Is Actually Known About His Scores

The scores Gates left behind

Bill Gates has never taken a publicly documented IQ test. What the Microsoft co-founder did leave is a trail of standardized results unusually complete for a living public figure. He graduated from Seattle's Lakeside School in 1973 as a National Merit Scholar. Wikipedia and Biography.com both report that he scored 1590 out of 1600 on the SAT, and Biography.com adds that for years he mentioned the score when introducing himself.

Gates confirmed the math half in his own words. In Source Code, his 2025 memoir of his early years, he describes the students in Harvard's Math 55 and writes: “All of us had 800s on our math SAT.” He entered Harvard in the fall of 1973.

Those are the facts. They describe a teenager at the ceiling of the country's main college-admission test. They do not describe an IQ score, and Gates has never claimed one.

Where the 160 figure comes from

The number most often attached to Gates online is 160. No site that repeats it names a test, an examiner or a date. It appears to come from feeding his SAT through a conversion formula, then rounding up.

The link between the two tests is real. In a 2004 paper in Psychological Science, Meredith Frey and Douglas Detterman reported that SAT scores correlated at .82 with general intelligence and published equations for converting one to the other. But three problems break the conversion for Gates.

• The ceiling. A 1590 sits 10 points below the maximum. A test cannot measure ability beyond its top score, so it shows that Gates reached the top of the SAT's range, not how far past it he could go.
• The group formula. Conversion equations describe averages across many students. Applied to one person at the extreme, the error band is wide.
• The era. Gates tested in the early 1970s, on a scale later recentered in 1995. Modern conversion tables do not map cleanly onto that version.

The circulating claim of an IQ of 160 would place Gates at roughly 1 in 31,600 people, the upper limit the WAIS-IV reports. See what IQ 160 means. A number that rare requires a real test. None exists.

Math 55: Gates's own verdict

The most revealing evidence comes from Gates himself. As a Harvard freshman he enrolled in Math 55, the university's notoriously demanding honors course, taught that year by John Mather. He earned a B+ in the first semester, which he calls an achievement in that class. Then he measured himself against the strongest students in the room and reached a hard conclusion: “I didn't have the gift of insight that sets apart the best mathematicians.”

That line matters for any discussion of his intelligence. Gates is describing a real gap between excellent and extraordinary, judged by someone who had just watched both at close range. It is the opposite of the inflated number the internet assigns him. For the mathematicians he had in mind, see our ranking of mathematicians by IQ estimate.

The pancake problem: a bound that lasted 30 years

Gates did produce one lasting piece of mathematics. The problem: given a stack of pancakes of different sizes, how many flips of a spatula, each reversing the top of the stack, are needed to sort any stack? Gates worked out an algorithm, and with the Harvard computer scientist Christos Papadimitriou he published “Bounds for Sorting by Prefix Reversal” in Discrete Mathematics, volume 27, in 1979. The paper lists his affiliation as Microsoft, Albuquerque, New Mexico. He was 23.

The paper proved an upper bound of (5n+5)/3 flips. It stood as the best known result for roughly three decades, until researchers at the University of Texas at Dallas lowered it to 18n/11 in work published around 2009. For a college dropout running a young company, it is a striking entry on the record.

The evidence in code

Gates's programming record starts early and is well documented. When he was in eighth grade at Lakeside, the school's Mothers' Club used proceeds from a rummage sale to buy a Teletype Model 33 terminal and computer time on a General Electric machine. His first program on it was a tic-tac-toe game. In 1971 a Lakeside teacher recruited him and his classmate Kent Evans to automate the school's class scheduling.

• Age 17: formed Traf-O-Data with Paul Allen to process traffic-counter data.
• 1975: wrote a BASIC interpreter for the Altair 8800 with Allen and founded Micro-Soft, a blend of microcomputer and software. He left Harvard the same year.
• July 1980: IBM approached Microsoft, the start of the deal that produced MS-DOS for the IBM PC.
• November 20, 1985: Microsoft shipped the first retail version of Windows.

Gates has written that the logic, focus and stamina for long, complicated programs came naturally to him, along with an ability to hyperfocus. Those traits appear throughout the record. They are also exactly what an IQ test does not time.

Gates beside Jobs, Musk and von Neumann

Among technology founders, Gates has the most complete test record. Steve Jobs left a single childhood data point: a fourth-grade test that, by Walter Isaacson's account, placed him at a high school sophomore level. Elon Musk's biographer reports SAT scores of 670 verbal and 730 math. Neither man published an IQ, so any ranking among the three rests on different tests taken years apart. Our Gates vs. Jobs comparison weighs their careers instead.

Comparisons with the theoretical founders of computing are clearer, and Gates supplied the reason himself. John von Neumann made the fundamental discoveries Gates said he could not. The Gates vs. von Neumann page sets out that contrast between builder and theorist.

What the scores leave out

Test scores explain little of what Gates did after 1975. Microsoft's rise depended on licensing strategy, hiring and timing, none of which appears on the SAT. Since 2000, when he and Melinda French Gates created the Bill & Melinda Gates Foundation with $5 billion in stock, his work has been philanthropy at a global scale, another domain no intelligence test samples.

Formal honors followed. Britain made him an honorary Knight Commander of the Order of the British Empire in 2005, and he received the Presidential Medal of Freedom in 2016. Harvard gave him an honorary degree on June 7, 2007. He opened his commencement speech with a line that sums up the gap between credentials and ability: “I've been waiting more than 30 years to say this: ‘Dad, I always told you I'd come back and get my degree.’”

Method note

We report only scores Gates disclosed or that reputable publishers reported, with attribution. The 1590 SAT appears in Biography.com and Wikipedia; the 800 in math comes from Gates's own memoir, as quoted by Forbes. We did not convert either into an IQ. Readers curious about their own standing can use our practice IQ test, which is a screener rather than a clinical assessment. Here is how online tests compare with supervised ones.

Editorial standard: IQ figures for historical figures are retrospective estimates and are labeled as such; scores for living people appear only when the person disclosed them or a reputable outlet reported them. Corrections: contact the editors.