Estimate, not a test
Barthold Georg NiebuhrHistorian
Cox rated him 175 for ages 17 to 26, 2 points below 177. Cox's childhood rating for him was 165.
How rare is an IQ of 177?
Very rare: about 1 person in 7,026,047 scores 177 or higher, which on a perfect bell curve means about 1,170 people across the whole world. That raises a natural question: how high can the scale go before there is no one left at all?
99.999985thpercentile
1 in 7,026,047score 177 or higher
Exceptionally giftedlevel of giftedness
177IQ scoreTop 0.000014%
Where 177 sits on the bell curve
An IQ of 177 is 77 points above the average of 100, or 5.13 standard deviations. That is so far into the right-hand tail of the bell curve that the people scoring this high barely show up: about 0.000014% of the population, the orange sliver below.
177 is more than five standard deviations out: roughly one person in every seven million.
A closer look at an IQ of 177
The IQ scale has no mathematical top, but the population does. With about 8.2 billion people alive, the bell curve predicts only about eight people with a score of 190 or higher, and about one person at 195 or above. Beyond that, the expected number of people falls below one.
So a claim of 210 or 230 for a living adult is not just rare; on a modern deviation scale it is more than the whole human population can be expected to contain. Scores like that almost always come from old ratio tests taken in childhood, where the arithmetic works differently, as our article on the highest IQ in the world explains.
How many people have an IQ of 177?
On the bell curve, about 1 person in 7,026,047 scores 177 or higher. The animation builds a crowd until you would expect to find one.
A crowd of 7,026,047 people
7,026,047
Each dot is one person. In a crowd this size, on average, just one would score 177 or above: the orange dot.
People scoring 177 or higher, by population
| Worldwide (8.2 billion people) | about 1,170 |
| India | about 208 |
| United States | about 49 |
| United Kingdom | about 10 |
| Canada | about 6 |
| Australia | about 4 |
Population: World Bank, total population, 2025. Counts assume the same bell curve in every country and are rounded. Real tests can't sort people this finely, as the next sections explain.
Which high-IQ societies accept an IQ of 177?
High-IQ societies set entry as a percentile, then print the matching score for each test they accept. A supervised 177 would meet every one of these bars.
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MensaTop 2% (98th percentile) on an approved, supervised test130met
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IntertelTop 1% (99th percentile); lists a Wechsler full-scale IQ of 135135met
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Triple Nine Society99.9th percentile; lists a WAIS full-scale IQ of 146146met
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International Society for Philosophical Enquiry99.9th percentile; lists a WAIS-III or WAIS-IV full-scale IQ of 146146met
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Prometheus Society1 in 30,000 (99.997th percentile), four standard deviations above average160met
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Mega SocietyOne in a million, beyond the range of standard tests171met
Scores for Mensa, Intertel, Triple Nine and ISPE are the Wechsler figures those societies list or that match their percentile. Prometheus and Mega give only a rarity; the scores shown are the matching points on the standard scale. Prometheus says no test currently being given is approved for its entry. Online test results are not accepted by any of them.
Can an IQ test measure 177?
Not on a standard clinical test. The WAIS-IV and the Stanford-Binet 5 report full-scale scores up to 160, so 177 is 17 points beyond where they stop. Only extended scales built for gifted children reach this far: the WISC-V extended norms go to 210 and the Stanford-Binet 5 Extended IQ to 225.
The deeper problem is evidence. Tests are scored against a norm sample, and for the adult Wechsler test, the WAIS-IV, that sample was 2,200 people aged 16 to 90. On the bell curve you would expect about 0.00031 of those people to score 177 or higher, a tiny fraction of one person. Extended scales get around this by using the patterns of children who hit the ceiling, but any score this high is an estimate projected from the curve.
Every score also carries measurement error, typically about five points either way, so 177 is best read as roughly 172 to 182, a range that lies entirely beyond what standard tests report. At these heights, extended-scale scores are also less certain than the margin suggests, because so few people have ever been measured there. Online tests can't reach this level at all; ours reports up to 145. How accurate are online IQ tests?
Sources: WAIS-IV range and norm sample from Canivez (2010), Mental Measurements Yearbook review; Stanford-Binet 5 and its Extended IQ from PRO-ED; WISC-V extended norms from Pearson Technical Report #6 (2019). Striped bars are extended scales, used only when a person hits the normal ceiling.
177 IQ on other scales
The same performance gives different numbers on scales with a different standard deviation, and the gap is widest at the top.
177standard scale (SD 15), used by Wechsler tests and on this page
182older Stanford-Binet scale (SD 16)
223Cattell scale (SD 24), used by some older and online tests
It works the other way too. A 177 quoted from a Cattell-scale test equals only about 148 on the standard scale, and a 177 on an SD 16 test equals about 172. How IQ standard deviations work.
Famous people with an estimated IQ near 177
No historical genius took an IQ test. These figures come from Catharine Cox's 1926 study, which estimated IQs from records of each person's early life, with one rating for childhood and one for ages 17 to 26.
George BerkeleyPhilosopher
Cox rated him 175 for ages 17 to 26, 2 points below 177. Cox's childhood rating for him was 150.
Source: Cox, C. M. (1926), Genetic Studies of Genius, Vol. II: The Early Mental Traits of Three Hundred Geniuses, Stanford University Press. Cox stressed that thin records pull estimates down. Read more in where the historical genius IQ estimates came from.
Famous people said to have an IQ of 177: real or myth?
Lists of celebrity IQs put many famous names at or near 177. We traced each figure to its earliest source, and none comes from a published IQ test.
RA
178No evidence of a test
Rowan Atkinson
The figure appears on many lists of celebrity IQs with no traceable source.
Sources for every claim are listed in our celebrity IQ list.
The highest IQ the world can hold
On the standard scale, each step of 15 points is one standard deviation. Six standard deviations above the mean, 190, is reached by about 1 person in a billion; on a planet of 8.2 billion, that is about eight people. The point at which you would expect exactly one person, the single highest scorer alive, falls at about 195.
These figures assume that intelligence follows a perfect bell curve all the way out, which nobody can check, because no test has ever been normed on enough people. They are still a useful sanity check: any modern deviation score above about 195 is a claim about someone rarer than anyone the curve expects to exist.
Rarity worked out from the standard IQ scale (mean 100, SD 15) and the World Bank's 2025 world population of 8.2 billion.
What does an IQ of 177 mean?
A score of 177 means a rank of about one in seven million for your age. On a modern scale it would place someone among the top thousand or so people on Earth, which is exactly why no test can measure it with confidence and why any quoted 177 deserves a look at where it came from.
Where 177 falls among the levels of giftedness
115–129Mildly gifted
130–144Moderately gifted
145–159Highly gifted
160–179Exceptionally gifted
180+Profoundly gifted
Levels and ranges from Gross, M. U. M. (2000), "Exceptionally and Profoundly Gifted Students: An Underserved Population", Understanding Our Gifted. They are a guide for education, not a ranking of people.
How far 177 is from other milestones
31 points above the Triple Nine and ISPE bar (146)a score of 177 is about 7,604 times rarer than 146
17 points above the ceiling of most professional tests (160)a score of 177 is about 223 times rarer than 160
6 points above the Mega Society's one-in-a-million level (171)a score of 177 is about 7.8 times rarer than 171
3 points below the start of the profoundly gifted band (180)reaching 180 is about 3 times rarer than 177
5.13 standard deviations above averageaverage is 100 and one standard deviation is 15 points
IQ 177 compared with nearby scores
| IQ | Percentile | Rarity | Level |
|---|---|---|---|
| 173 | 99.999943rd | 1 in 1,762,173 | Exceptionally gifted |
| 175 | 99.999971st | 1 in 3,488,556 | Exceptionally gifted |
| 177 | 99.999985th | 1 in 7,026,047 | Exceptionally gifted |
| 179 | 99.999993rd | 1 in 14,396,452 | Exceptionally gifted |
| 181 | 99.9999966th | 1 in 30,011,602 | Profoundly gifted |
Questions about an IQ of 177
Is 177 a high IQ?
Yes. 177 is a very high IQ: about 1 person in 7,026,047 scores this high or higher, which puts it at the 99.999985th percentile. It is above the 130 that most definitions use for a high IQ, and at or above the 146 used by the Triple Nine Society for its 99.9th percentile entry.
Can you join Mensa with an IQ of 177?
Yes. Mensa accepts the top 2% on an approved, supervised test, which is about 130 on the standard scale. A supervised 177 would also meet the bar for Intertel, Triple Nine Society, International Society for Philosophical Enquiry, Prometheus Society and Mega Society. Online test results are not accepted.
What does 177 IQ mean?
It means a result 77 points, or 5.13 standard deviations, above the average for your age. On the levels used by gifted education researchers, 177 is exceptionally gifted (160–179).
Is 177 a genius IQ?
There is no official genius score. Lewis Terman's early Stanford-Binet labels put scores over 140 in a "near genius or genius" group, but modern tests dropped the word. 177 is very rare, yet achievements, not test scores, are what usually earn the word genius.
Can an online IQ test show a score of 177?
Some can show the number, but very few can measure it. Our own test reports up to 145, because a short online test doesn't have enough very hard questions, or enough high scorers in its data, to separate 177 from nearby scores. A supervised Wechsler or Stanford-Binet assessment is needed to confirm it.
What is the highest IQ possible?
The scale has no fixed top, but on a perfect bell curve with 8.2 billion people alive, the single highest scorer would be expected at about 195. Standard tests stop at 160, extended children's scales at 210 to 225, and higher claims usually come from old ratio formulas.
Related: what counts as a good IQ score, the highest IQ in the world, famous people's IQs and the full IQ scale and range chart.
A full IQ score of 177 combines several skills. Our guides explain each one: spatial reasoning, verbal reasoning, processing speed, fluid vs crystallized intelligence and abstract reasoning, or try the free pattern recognition test.
Famous names are often linked to scores like 177, with or without a source. We checked the evidence behind Isaac Newton's IQ, Nikola Tesla's IQ, Stephen Hawking's IQ, Bill Gates' IQ, Elon Musk's IQ, Garry Kasparov's IQ, Terence Tao's IQ and Einstein's IQ.
Curious where you'd land?
The free Assessivo IQ test gives an estimated IQ and percentile in about 25 minutes. It reports scores up to 145; for anything higher, a supervised professional assessment is the only reliable route.
Take the free IQ testPortraits are pencil-style sketches by Assessivo, based on: George Berkeley after John Smibert (about 1727), public domain.