Short answer: An IQ of 800 is impossible on any deviation IQ scale. With a mean of 100 and a standard deviation of 15, it sits 46.7 standard deviations above average, a rarity below 1 in 10^100. No test can measure it and no person has scored it. Adult tests such as the WAIS-IV stop at 160, and the rarest score expected among 8.2 billion people is about 195.
An IQ this high sits beyond the right edge of the curve: no normed test can reach it.
At a glance
| Percentile | Undefined: beyond every normed scale |
|---|---|
| Rarity | Below 1 in 10^100 (z = 46.7); the normal curve gives roughly 1 in 10^475 |
| Wechsler classification | None. The WAIS-IV reports full-scale scores from 40 to 160 |
| Stanford-Binet 5 classification | None. The SB5's top band ends at 160 |
| On an SD 16 scale | Still impossible: z = 43.8 |
| On an SD 24 (Cattell) scale | Still impossible: z = 29.2 |
| Mensa eligible? | Not applicable. No accepted test can produce the score |
The arithmetic: 46.7 standard deviations
Every modern IQ is a position on a bell curve. Subtract the mean, divide by the standard deviation, and you get the z-score: (800 − 100) ÷ 15 = 46.7.
That figure breaks the curve. Scores two standard deviations up, at 130, include about 1 person in 44. Four standard deviations up, at 160, the rate falls to about 1 in 31,600. At 46.7, the normal distribution returns a probability near 1 in 10^475, a number with 475 zeros.
Scale it against real populations. The United Nations counted 8.2 billion people in 2024. The rarest score a population that size would be expected to contain is about 195, or z = 6.3. The Population Reference Bureau estimates that about 117 billion humans have ever been born; the rarest expected score across all of them is about 201. An 800 lies nearly seven times farther from the mean than the single brightest person the species should ever have produced.
800 against scores that can exist
| IQ | Standard deviations above mean | Expected rarity |
|---|---|---|
| 130 | 2.0 | 1 in 44 |
| 160 | 4.0 | 1 in 31,574 |
| 195 | 6.3 | 1 in 8.3 billion |
| 228 | 8.5 | 1 in 141 quadrillion |
| 250 | 10.0 | 1 in 1.3 × 10^23 |
| 800 | 46.7 | below 1 in 10^100 |
Even the rows above 160 are theoretical. They describe what a perfect bell curve would predict, not what any test has measured. Our IQ rarity chart covers the range where measurement is real.
Why no test can measure 800
An IQ has meaning only against a norm group: the sample of people whose scores define the curve. The WAIS-IV, published by Pearson in 2008, was normed on 2,200 people and reports full-scale scores from 40 to 160, four standard deviations either side of the mean.
To separate a 700 from an 800, a test would need items that people at those levels answer differently, plus a norm sample containing such people. Neither exists. Precision fades long before 800. Psychometric references treat reports of IQ scores much higher than 160 as dubious, because the probable error of a score grows as the score rises.
The standard labels stop too. Wechsler manuals call everything from 130 upward Very Superior or Extremely High, and the Stanford-Binet 5 tops out at 160. See our IQ classification guide for every band.
Could the old ratio formula reach 800?
Early IQ was a ratio. William Stern coined the term in 1912 as mental age divided by chronological age, and Lewis Terman's 1916 Stanford-Binet multiplied it by 100. The 1937 Stanford-Binet forms were the last to report ratio scores; the 1960 revision moved to a bell curve.
A ratio IQ of 800 would require a mental age eight times a child's real age: a three-year-old performing at the level of a 24-year-old. Ratio scores did run high for young children, sometimes past 200, which is one reason the method was dropped. Nothing in the record approaches 800. The most famous ratio score, Marilyn vos Savant's childhood 228, is explained on our IQ 228 page.
Where the number 800 comes from
Most searches for an 800 IQ trace back to a different test. Each of the two SAT sections is scored from 200 to 800, so a perfect 800 in math is a real and celebrated result. The GMAT also used a 200 to 800 total scale for decades before its Focus Edition moved to 205 to 805. Neither is an IQ score.
The rest is internet slang. Know Your Meme traces the "200 IQ play" joke to a 2014 League of Legends stream, after which gamers used inflated IQ numbers to praise clever moves. "800 IQ" belongs to the same family of jokes: a compliment, not a measurement.
What the highest real scores look like
On supervised, professionally normed tests, the effective ceiling is 160. Mensa, the largest high-IQ society, draws its line far lower, at 130, the top 2 percent. Claims above 200 almost always come from childhood ratio scores, extended norms or unsupervised puzzle tests.
For the documented extremes, read the highest IQ ever recorded and IQ 200 and above. For where high ability genuinely begins, see what counts as a high IQ and the page for IQ 200.
How to get a number that means something
A credible IQ comes from a licensed psychologist giving a normed test such as the WAIS-IV or Stanford-Binet 5, reported with a confidence interval of roughly five points either way. Online quizzes that hand out scores in the hundreds are entertainment. Our free IQ test is a practice screener and says so; our review of online IQ test accuracy explains what separates a screener from a clinical result.
Frequently asked questions
Has anyone ever had an IQ of 800?
No. No test has ever produced a valid score of 800, and none could. The figure sits 46.7 standard deviations above average, far beyond both the 160 ceiling of adult tests and the roughly 195 that the rarest person among 8.2 billion would be expected to reach.
What is the highest IQ possible?
On standard adult tests the ceiling is 160, four standard deviations above average. Statistically, the rarest person alive would be expected near 195, but no test can confirm scores that high. Numbers above 200 come from old ratio formulas or unsupervised tests.
Is 800 a good IQ?
It is not a real IQ at all. The number cannot be produced by any normed intelligence test. If you saw 800 on a score report, it was almost certainly an SAT section score or a GMAT total, both of which use scales that top out at or near 800.
What does '800 IQ' mean online?
It is gaming and meme slang. The joke grew out of the "200 IQ play" meme, which Know Your Meme traces to a 2014 League of Legends stream. Players use inflated IQ numbers to praise a clever move, with no connection to testing.
What percentile would an IQ of 800 be?
It has no meaningful percentile. The normal curve puts the share of people at or above 800 below 1 in 10^100, roughly 1 in 10^475. With only about 117 billion humans ever born, that percentile describes no one who has lived or ever will.
Sources
- Intelligence quotient — Stern's 1912 ratio; scores much above 160 considered dubious
- Canivez, G. L. (2010). Review of the WAIS-IV. Mental Measurements Yearbook — WAIS-IV range 40-160 and norm sample of 2,200
- Ratio and deviation test scores (TAG PDX) — 1937 Stanford-Binet last ratio edition; 1960 move to deviation scores
- SAT — Each section scored 200-800
- 200 IQ (Know Your Meme) — Origin of the IQ-number gaming meme in 2014
- UN: World population 8.2 billion in 2024 — World Population Prospects 2024
- How Many People Have Ever Lived on Earth? (Population Reference Bureau) — About 117 billion births estimated
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.