IQ 250 — How Rare It Is, What It Means & Famous People With This Score

Updated 2026-09-26 · Based on historical estimates and psychometric research

An IQ of 250 is beyond the 99.9999999th percentile: 1 in 131 sextillion on the normal curve. On today’s 8.2 billion people that is fewer than one person. It sits 10.00 standard deviations above the average and is classed as profoundly gifted.

Percentilebeyond the 99.9999999th
How rare1 in 131 sextillion
People alive with this score or higherfewer than one — on the normal curve, no one alive
Standard deviations above the average of 100+10.00
Classificationprofoundly gifted
Mensa (top 2%, 130 and above)qualifies

Is 250 a good IQ?

It is not a score any modern adult test can give: they top out at 160. On the normal curve it is 1 in 131 sextillion, so claims of an IQ of 250 are estimates, not measurements.

How many people have an IQ of 250 or higher?

On the normal curve used by modern tests, fewer than one person alive: 1 in 131 sextillion. Every published claim this high is an estimate.

Standard versions of the leading adult tests, the WAIS-IV and the Stanford–Binet 5, top out at 160. Scores above that come from old ratio formulas used on children, from extended norms or from extrapolation, so treat them as estimates, not measurements.

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250
Unmeasurable / Profoundly Gifted
Beyond the measurable range — the normal curve predicts fewer than one such person on Earth (normal curve, SD 15; theoretical above 160)

What Does an IQ of 250 Mean?

An IQ of 250 is extraordinarily rare — approximately 1 in 131 sextillion of the world's population. At this level, individuals demonstrate cognitive capabilities so far beyond the norm that standard IQ tests may not accurately measure their abilities. Many testing instruments have a ceiling around 160-170, making scores above this range estimates based on exceptional achievement.

People at this level have historically been responsible for paradigm-shifting discoveries, revolutionary theories, and works of profound creative genius. The gap between an IQ of 250 and the average of 100 represents a cognitive difference roughly equivalent to 10.0 standard deviations above the mean.

Classification
Unmeasurable
Percentile
99.9999999%
Std. Deviations
+10.0σ
Rarity
~1 in 131 sextillion

Where IQ 250 Falls on the Bell Curve

IQ 250 7085100115130145160175190

The highlighted area shows the percentage of the population scoring at or above IQ 250. The dashed line marks the exact position of this score on the normal distribution.

Famous People With an IQ of 250

There are 2 geniuses in our database with an estimated IQ of 250:

Ainan Celeste Cawley
Singapore · 1999
William James Sidis
Manhattan · 1898–1944

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About IQ Scores: IQ (Intelligence Quotient) scores follow a normal distribution with a mean of 100 and a standard deviation of 15. Historical IQ estimates for famous individuals are approximations based on their demonstrated achievements, not direct test results. These estimates should be considered illustrative rather than definitive.

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