Short answer: An IQ of 133 is very superior: higher than about 98.6 percent of people, or roughly 1 in 72. It sits three points above Mensa's Wechsler cutoff of 130, a margin wide enough to survive most measurement error. On an SD 16 scale the same standing reads as about 135; on the SD 24 Cattell scale, about 153.
Shaded: the share of people who score higher on a mean-100, SD-15 scale.
At a glance
| Percentile | 98.61st (1.39% score higher) |
|---|---|
| Rarity | About 1 in 72 |
| Wechsler classification | Very Superior (WAIS-IV) / Extremely High (WAIS-5) |
| Stanford-Binet 5 classification | Gifted or very advanced |
| On an SD 16 scale | About 135 |
| On an SD 24 (Cattell) scale | About 153 |
| Mensa eligible? | Yes, with a three-point cushion on a supervised test |
Reading a score of 133
A 133 lies 2.2 standard deviations above the mean. It lands at the 98.61st percentile, which leaves 1.39 percent of the population above it. In a school of 1,000 pupils, about 14 would score this high or higher.
Every major scale treats 133 as elite. The WAIS-IV files it under Very Superior, the WAIS-5 under Extremely High, and the Stanford-Binet 5 under Gifted or very advanced, a band that runs from 130 to 139. The IQ scale classification guide lays the bands side by side.
Where 133 sits among its neighbors
| IQ | Percentile | Higher scorers | Rarity |
|---|---|---|---|
| 131 | 98.1 | 1.9% | 1 in 52 |
| 132 | 98.4 | 1.6% | 1 in 61 |
| 133 | 98.6 | 1.4% | 1 in 72 |
| 134 | 98.8 | 1.2% | 1 in 85 |
| 135 | 99.0 | 1.0% | 1 in 102 |
Moving from 130 to 133 shrinks the qualifying pool from 2.3 percent of people to 1.4 percent, a cut of nearly 40 percent. Two more points reach the 99th percentile. The IQ rarity chart runs the same arithmetic across the whole curve; see also IQ 132 and IQ 134.
One ability, three numbers
IQ scales differ in how many points they assign to one standard deviation. Modern Wechsler tests and the Stanford-Binet 5 use 15. Older Stanford-Binet editions used 16. The Cattell scale uses 24. The same 98.6th-percentile performance therefore prints as 133, about 135 or about 153, depending on the test.
Norms age, too. A 2015 meta-analysis by Jakob Pietschnig and Martin Voracek, covering nearly four million test takers from 1909 to 2013, estimated full-scale gains of about 0.28 points a year. A test scored against 15-year-old norms can therefore flatter a result by roughly four points. Several countries, including Denmark and Norway, have since recorded declines. A 133 on current norms is worth more than a 133 on stale ones.
A margin that holds up
Any single IQ score carries an error band of about five points either way, so a measured 133 is best read as somewhere between 128 and 138. Most of that band lies above Mensa's line. Mensa International admits people at or above the 98th percentile on an approved, supervised test; the steps are in how to join Mensa.
Few eligible people take the step. The top 2 percent of a world population of roughly 8.3 billion is about 166 million people. Mensa counts around 150,000 members in more than 90 countries. By that arithmetic, fewer than one qualifier in a thousand belongs.
Is 133 a good IQ?
Statistically, it is excellent. Practically, its reach has limits. The 1996 American Psychological Association task force led by Ulric Neisser found IQ correlated about .3 to .5 with measures of job performance. Correlations of that size shift probabilities across large groups. They leave room for wide individual variation.
A 133 signals quick abstract reasoning and a strong capacity to absorb complex material. It does not measure persistence, practical judgment, creativity or the willingness to finish hard work. Our overview of what makes an IQ high covers where the advantage shows up and where it fades.
Confirming a 133
A number worth quoting comes from a licensed psychologist using a current edition of a standardized test, such as the WAIS-IV, WAIS-5 or Stanford-Binet 5. Ask which edition was used and when its norms were collected. Mensa accepts only supervised results. Our free IQ test is a practice screener for a quick estimate, not a clinical score; how accurate online IQ tests are explains the gap.
Nearby scores
- IQ 131: the first whole number past the 98th percentile.
- IQ 135: the 99th percentile, 1 in 102.
- IQ 137: three points shy of the old 140 genius label.
Frequently asked questions
Is 133 a good IQ score?
Yes. A 133 is higher than about 98.6 percent of people and falls in the Very Superior band of the WAIS-IV. Roughly 1 in 72 people score at or above it. It is strong evidence of fast abstract reasoning, though it predicts group tendencies rather than individual outcomes.
How rare is an IQ of 133?
About 1 in 72 people score 133 or higher on a test with a mean of 100 and a standard deviation of 15. That is 1.39 percent of the population. In a city of one million, roughly 13,900 residents would reach that level.
Is 133 enough for Mensa?
Yes. Mensa's cutoff on Wechsler-type tests is 130, the 98th percentile. A 133 clears it by three points, provided it came from an approved test that was properly administered and supervised. Online results do not qualify, whatever the number.
Why do different IQ tests give different scores?
Three reasons dominate. Tests use different standard deviations, so the same standing prints as 133 on one and about 153 on the Cattell scale. Norms age, and older norms tend to inflate results. And every score carries measurement error of roughly five points, so two careful tests can still disagree.
Sources
- IQ classification (Wikipedia) — WAIS-IV, WISC-V and Stanford-Binet 5 bands
- Mensa International: Getting your IQ tested FAQs — 98th percentile rule, supervised tests only
- Mensa International (Wikipedia) — About 150,000 members in 90+ countries
- Pietschnig & Voracek (2015), One Century of Global IQ Gains, Perspectives on Psychological Science — Full-scale gains of about 0.28 points per year
- Flynn effect (Wikipedia) — Rates of gain; reversals in Denmark and Norway
- Intelligence: Knowns and Unknowns (Neisser et al., 1996) — IQ and job performance correlations of .3 to .5
- World population (Wikipedia) — About 8.3 billion people in 2026
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.
