Famous People's IQ - And the Highest IQ Ever Recorded
Einstein's IQ is "160." Newton's was "190." Someone once made the Guinness Book with "228." You have seen these numbers on quiz sites, in listicles, and in captions under old photographs. Here is the honest headline: almost every famous IQ you have ever read is an estimate, not a measured score. Albert Einstein never took an IQ test. Neither did Newton, Leonardo, or Tesla. The tidy three-digit numbers attached to them were assembled decades later by researchers, journalists, or fans working backward from what these people accomplished.
That does not make the numbers worthless, but it does mean you should read them the way you read a movie's box-office "adjusted for inflation" figure: a reasonable model, not a fact carved in stone. This page is the reference hub for celebrity and historical IQ claims. Below you will find where these numbers actually come from, a big table separating the handful of real test scores from the many guesses, and a clear-eyed look at the "highest IQ ever recorded" debate - the Sidis 250s, the vos Savant 228, the Tao 230 - and why modern psychology does not accept any of them at face value. As of 2026, this is still the state of the evidence.
Where do celebrity IQ numbers even come from?
Short answer: three sources, and none of them is a modern, standardized test taken by the person in question as an adult. Here they are, weakest to strongest.
| Method | How it works | Why it is unreliable |
|---|---|---|
| Historiometric estimate | A researcher reads biographies and back-estimates a childhood IQ from documented achievements (Cox, 1926). | Rewards people who left detailed records; measures fame and paper trail as much as intellect. |
| Test-score conversion | A childhood SAT, entrance exam, or "high-range" test result is converted into an IQ-like number. | Conversion formulas are rough; tests are extremely noisy at the extremes. |
| Self-report or attribution | The person, a relative, or a website simply states a number. | No verification; often circulates until it looks official. |
The Cox 1926 study - the source of most "historical genius" numbers
Most of the famous historical figures (Newton ~190, Leonardo ~200, Goethe ~210+) trace back to a single source: Catharine Cox's 1926 dissertation The Early Mental Traits of Three Hundred Geniuses, the second volume in Lewis Terman's Genetic Studies of Genius series. Cox and her team read biographies of 301 eminent people who lived before IQ tests existed, then estimated an IQ from what each person could demonstrably do by a given age. In her ranking, Goethe came out on top (estimated around 210-225 depending on the correction used), with Leonardo da Vinci near 200 and Isaac Newton around 190-192.
It was serious scholarship for its time. It is also a measure of the surviving biographical record, not of a brain. A prodigy whose parents kept letters and diaries scores high; an equally brilliant person from a poor family with no paper trail scores low. Cox knew this and openly said her figures were minimum estimates biased by incomplete records. The popular internet versions strip out that caveat and present the numbers as if Newton sat an exam.
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The reference table: measured vs. estimated
Here is the honest scorecard for the names you most often see. The "Measured or estimated?" column is the one that matters. Read every "estimated" as "a model, not a fact," and every living-person number as "commonly cited as," never as proven.
| Person | Commonly cited IQ | Measured or estimated? | Source / method |
|---|---|---|---|
| Albert Einstein | ~160 | Estimated (never tested) | Popular media; figure has ranged 150-207 with no primary source |
| Isaac Newton | ~190 | Estimated | Cox (1926) historiometric |
| Leonardo da Vinci | ~200 | Estimated | Cox (1926) historiometric |
| Johann Wolfgang von Goethe | ~210-225 | Estimated (Cox's highest) | Cox (1926) historiometric |
| Nikola Tesla | ~180 | Estimated / anecdotal | Retrospective from achievements |
| John von Neumann | ~190 | Anecdotal | Colleague accounts; no test on record |
| Stephen Hawking | ~160 (widely repeated) | Never disclosed | Hawking said he had "no idea"; no known test |
| Terence Tao | ~220-230 | Estimated from childhood SAT | Age-8 SAT math 760/800, extrapolated |
| Marilyn vos Savant | ~228 | Measured (childhood ratio IQ) but disputed | 1937 Stanford-Binet at age 10; Guinness listing |
| William James Sidis | ~250-300 | Estimated / unverified | Single second-hand account (Sperling, 1946) |
| Christopher Langan | ~195-210 | Partly measured (contested) | TV segment; high-range and IQ tests |
| Kim Ung-yong | ~210 | Measured (childhood ratio IQ) | Old Stanford-Binet ratio formula as a child |
| Bill Gates | ~150-160 | Estimated / self-not-confirmed | Old SAT rumor; no confirmed IQ test |
| Elon Musk | ~150-155 | Estimated | Popular sites; no confirmed IQ test |
A few things jump out. Einstein and Hawking - the two names most people reach for first - were almost certainly never tested. Hawking, asked his IQ by a New York Times reporter in 2004, said he had no idea and added that "people who boast about their IQ are losers." The measured childhood scores (vos Savant, Kim Ung-yong) are real, but they use an old formula that inflates children's numbers. And the truly astronomical figures (Sidis, Tao's 230) are extrapolations that the people involved never claimed and, in Tao's case, actively downplays.
Why living celebrities' numbers are the shakiest of all
For modern figures like Elon Musk or Bill Gates, there is usually no test at all - just a number that appeared on a ranking site and got copied. Sometimes it is reverse-engineered from an old SAT score, which is not an IQ test and whose IQ conversion changed over the years. So when you see "Elon Musk's IQ is 155," read it as internet folklore. No credible, verifiable IQ score has been published for either man.
The "highest IQ ever recorded" debate
There is no single, verified "highest IQ ever," and the reason is baked into how the scale works. Here are the four names that dominate the argument, and why each number is contested.
- William James Sidis (~250-300). The most extreme figure and the least documented. There is no record of Sidis ever taking a standardized IQ test. The 250-300 claim comes from a single second-hand account: his sister told psychologist Abraham Sperling that an unnamed examiner had estimated his intelligence that high. No test paper, no examiner named, no data. Sidis was clearly a real prodigy - lecturing on four-dimensional geometry as a child - but the number is folklore.
- Marilyn vos Savant (228). This one is a real test result, which is why it is famous. At age 10 in 1956 she took the 1937 Stanford-Binet and her mental age worked out to 22 years 10 months, giving a "ratio IQ" of 228. Guinness listed her as "Highest IQ" from 1985 to 1989. But that ratio formula (mental age divided by actual age) produces wildly inflated numbers for gifted children and was abandoned by the 1960s. On an adult high-range test years later, she scored the equivalent of about 186 - still extraordinary, but far from 228.
- Terence Tao (~220-230). Tao is a Fields Medalist and one of the greatest living mathematicians, so it is tempting to accept a huge number. But the 230 is an extrapolation: at age 8 he scored 760/800 on the SAT math section, and researchers back-calculated an IQ from how statistically rare that is. Tao himself has said the estimate is extremely noisy at that level and that "greater than 175" is a more honest statement.
- Christopher Langan (~195-210) and Kim Ung-yong (~210). Langan's number comes largely from a 1999 TV segment. Kim's 210 is a genuine childhood Stanford-Binet result - but again using the old ratio formula that inflates young prodigies. Neither is comparable to a modern adult deviation IQ.
Why nobody credibly "has" a 200+ IQ under modern scaling
Modern IQ is a deviation score: 100 is average, and every 15 points is one standard deviation. A score of 160 is already four standard deviations above average - roughly 1 in 30,000 people. A score of 200 would be nearly seven standard deviations out, rarer than 1 in a billion, which means there are not enough people on Earth to have ever calibrated what a "200" even means. Standard tests are built with a ceiling around 160-170 for exactly this reason. Anything above that comes from one of the shaky sources above: the old childhood ratio formula, non-standardized "high-range" puzzle tests, biographical estimation, or family attribution.
This is also why Guinness World Records retired its "Highest IQ" category in 1990 - the editors concluded IQ tests were simply too unreliable to crown a single record holder. When the record-keepers give up, that tells you something.
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So what should you take away?
Three things. First, treat every famous IQ number as an estimate unless you can point to an actual, standardized test - and for the biggest names (Einstein, Hawking, Newton, Leonardo), no such test exists. Second, the handful of real childhood scores (vos Savant, Kim Ung-yong) are inflated by an outdated formula and are not comparable to a modern adult score. Third, the ceiling of real tests is around 160-170; numbers above that are extrapolations, not measurements.
The productive move is not to chase a mythical 200. It is to get one honest, current data point about yourself and understand where it sits on the modern scale. That is something you can actually do - unlike, apparently, Einstein.
More famous people's IQs
Curious about a specific person? These break down the commonly cited number, where it came from, and whether it was ever actually measured.
- Scientists and thinkers: Richard Feynman, Christopher Langan, Jordan Peterson, the scientists with the highest IQs
- Actors and entertainers: Geena Davis, Sharon Stone, James Woods, Jodie Foster, Marilyn Monroe, Sylvester Stallone, Ashton Kutcher, Steve Martin, Ashley Rickards, Quentin Tarantino, Natalie Portman, Mayim Bialik, Rowan Atkinson, Conan O'Brien, Ken Jeong, Lisa Kudrow, Cindy Crawford, Dolph Lundgren, Matt Damon, Weird Al Yankovic, James Franco, David Duchovny, Emma Watson, Hedy Lamarr, the smartest actors in Hollywood
- Musicians and TV: Shakira, Alicia Keys, Snoop Dogg, Carol Vorderman, Dexter Holland, Kesha, Brian May, Brian Cox, Taylor Swift
- Business and tech: Mark Zuckerberg, Walter O'Brien, Tai Lopez
- Prodigies and record claims: Alexis Martin, Ainan Cawley, Adragon De Mello, Tara Sharifi, Lydia Sebastian, the smartest person alive today
- Roundups: artists with high IQ, famous people with average IQ, the woman with the highest IQ, geniuses with dyslexia, highest IQ chess players, highest IQ in sports, US presidents ranked by IQ, highest-IQ billionaires and CEOs, musicians with the highest IQ, child prodigies, highest-IQ NBA players, smartest rappers, streamer IQ, the smartest minds from India, smartest soccer players, the smartest Japanese minds, the smartest Americans
Frequently asked questions
Q: What was Einstein's IQ?
A: There is no real answer - Einstein never took an IQ test. He died in 1955, and the "160" you see everywhere is a retroactive estimate that popular media settled on. Published guesses have ranged from about 150 to over 200 with no primary source behind any of them. His genius is documented through his physics, not through a score.
Q: Who has the highest IQ ever recorded?
A: No one holds a verified record - Guinness retired the category in 1990 as too unreliable. The names most often cited are William James Sidis (~250-300, unverified), Marilyn vos Savant (228, a disputed childhood ratio score), and Terence Tao (~230, an extrapolation Tao himself downplays). None is a modern, standardized adult IQ.
Q: Are the IQ numbers for historical geniuses like Newton and Leonardo real?
A: No, they are estimates from Catharine Cox's 1926 study. Cox read biographies of 301 eminent people and back-estimated childhood IQs from documented achievements. The method measures the surviving paper trail as much as raw intelligence, and Cox herself called the figures minimum estimates biased by incomplete records.
Q: Why can't anyone score above 200 on a real IQ test?
A: Because modern tests have a ceiling around 160-170 and the math above it breaks down. IQ is a deviation score where 15 points equals one standard deviation. A 200 would be about seven standard deviations from average - rarer than 1 in a billion - so there is no population to calibrate it against. High numbers come from an old childhood formula or non-standard tests, not standard ones.
Q: What about Elon Musk's or Bill Gates's IQ?
A: Neither has a confirmed IQ test on record - the numbers you see are folklore. Figures like "Musk 155" or "Gates 160" are usually reverse-engineered from old SAT scores or simply invented by ranking sites, then copied until they look official. Treat them as "commonly cited," never as measured fact.
References
- Cox, C. M. (1926). The Early Mental Traits of Three Hundred Geniuses. Genetic Studies of Genius, Vol. II. Stanford University Press. Summary and data: IQ Comparison Site - Cox's estimates of 301 geniuses
- Wikipedia contributors. Marilyn vos Savant - childhood Stanford-Binet score, Guinness listing, and retirement of the "Highest IQ" category.
- PsyPost. What is the highest IQ ever recorded? The truth behind the numbers - overview of ratio vs. deviation IQ and why extreme scores are unreliable.
- Warne, R. (2023). The search for Albert Einstein's IQ - on the absence of any Einstein test and the origin of the "160" figure.
Last updated: July 13, 2026
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