Short answer: An IQ of 149 is very superior: higher than about 99.95 percent of people, roughly 1 in 1,838. It sits 3.27 standard deviations above the mean, clears Mensa's 130 line and the Triple Nine Society's 146. It is one point below 150, a round number with no special meaning in test manuals, and near the zone where scores become less precise.
Shaded: the share of people who score higher on a mean-100, SD-15 scale.
At a glance
| Percentile | 99.946th |
|---|---|
| Rarity | About 1 in 1,838 (0.054 percent score 149 or higher) |
| Wechsler classification | Very Superior (WAIS-IV) / Extremely High (WAIS-5) |
| Stanford-Binet 5 classification | Very gifted or highly advanced |
| On an SD 16 scale | 152 |
| On an SD 24 (Cattell) scale | 178 |
| Mensa eligible? | Yes, far above the 130 line; also above the Triple Nine Society's 146 |
What an IQ of 149 means
A 149 sits 49 points above average. In standard-deviation terms that is 3.27, deep in the right tail of the bell curve. In a town of 10,000 adults, about five would be expected at this level or higher.
Both major test families reserve their top labels for it. Wechsler tests call it Very Superior or Extremely High. The Stanford-Binet 5 places 149 in its highest band, very gifted or highly advanced, which starts at 145. Our IQ classification guide lists every band.
How 149 compares with 150 and its neighbors
| IQ | Percentile | Rarity |
|---|---|---|
| 146 | 99.89 | 1 in 924 |
| 148 | 99.93 | 1 in 1,455 |
| 149 | 99.95 | 1 in 1,838 |
| 150 | 99.96 | 1 in 2,331 |
| 151 | 99.97 | 1 in 2,968 |
Out here, one point changes rarity by about 25 percent. The percentile barely moves while the head count shrinks fast. That is the geometry of the curve's tail, charted in full on our IQ rarity chart.
Does falling one short of 150 matter?
No manual draws a line at 150. The Wechsler top band begins at 130; the Stanford-Binet 5 top band begins at 145. The appeal of 150 is the round number.
Measurement erases the distinction anyway. A 95 percent confidence interval of roughly ten points means a reported 149 describes a likely true score between about 144 and 154. The same performance reads 152 on an SD 16 test and 178 on the Cattell scale, so a "150" from a friend may be a lower score than your 149.
Why precision fades this high
Every IQ is a comparison with a norm sample. The WAIS-IV was normed on 2,200 people. On a perfect bell curve, a sample that size would contain about one person at 149 or above. Scores this high therefore rest partly on statistical extrapolation, not on dozens of real peers who took the same items.
Tests also run short of hard questions near the top. The WAIS-IV full-scale ceiling is 160, only 11 points away. A person who answers nearly everything correctly hits the ceiling and cannot show more. Psychometric references note that high scores are less reliable than those near the median, and that the probable error of a score grows as the score rises.
A practical rule follows: at 149, a single test result is strong evidence of exceptional ability, and weak evidence of the exact number.
Does more ability still matter at 149?
The best evidence says yes. The Study of Mathematically Precocious Youth has followed thousands of children who scored in the top 1 percent by age 13. In a 2020 review, David Lubinski and Camilla Benbow reported "no threshold effect" for ability: within that already elite group, the top quarter earned doctorates, patents and publications at higher rates than the bottom quarter.
That supports the view that a 149 carries real advantages over a 135. It does not make the outcome certain. Interests, persistence and opportunity shaped which of those children became scientists, writers or neither. See the top 1 percent guide for how the tail is divided.
Getting a trustworthy 149
Choose an individually administered test with a high ceiling, such as the WAIS-IV, WAIS-5 or Stanford-Binet 5, given by an experienced examiner. Ask for the confidence interval and index scores. Online quizzes that report 149 are not evidence of anything at this level. Our free IQ test is a practice screener, and we explain why online IQ tests fall short. For membership options, start with our guide to joining Mensa.
Neighboring pages
- IQ 147: the Triple Nine threshold, about 1 in 1,157.
- IQ 150: the round number, about 1 in 2,331.
- IQ 155: nearing the WAIS ceiling.
Frequently asked questions
Is 149 a genius IQ?
Test manuals no longer use the word genius. A 149 is in the top classification band of every major test and rarer than 1 in 1,800. Whether anyone is a genius depends on what they create, not on a score.
What percentile is an IQ of 149?
About the 99.95th percentile on a scale with mean 100 and SD 15. Roughly 0.054 percent of people score at or above 149, or about 1 in 1,838.
Is 149 very different from 150?
No. The two scores fall inside each other's confidence intervals, and neither the Wechsler nor the Stanford-Binet manual treats 150 as a boundary. The main difference is psychological: 150 is a round number.
Can an IQ of 149 join the Triple Nine Society?
Yes, if it comes from an accepted, supervised test. The Triple Nine Society admits the 99.9th percentile: at least 146 on SD 15 tests such as the WAIS, 149 on SD 16 tests and 173 on the Cattell III-B.
How accurate is an IQ score of 149?
Accurate in rank, less so in the exact number. At this height, norm samples contain very few people and tests approach their ceilings, so the error band widens. Treat 149 as evidence of ability somewhere in the mid to high 140s or low 150s.
Sources
- Canivez, G. L. (2010). Review of the WAIS-IV. Mental Measurements Yearbook — Norm sample of 2,200; range 40-160
- Lubinski, D., & Benbow, C. P. (2020). Intellectual precocity: What have we learned since Terman? Gifted Child Quarterly — No threshold effect within the top 1 percent
- Intelligence quotient — High scores less reliable than scores near the median
- IQ classification — Probable error increases as IQ increases; Wechsler bands
- Stanford-Binet 5 classification ranges — Top band 145-160
- Triple Nine Society — 146 on SD 15, 149 on SD 16, 173 on Cattell III-B
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.