How rare is an IQ of 155?
An IQ of 155 is at the Genius level level (Top ~0.1%). IQ follows a normal distribution with a mean of 100 and a standard deviation of 15, and an IQ of 155 sits as follows.
Deviation score
86.7
Top
0.01%
Rarity
1 in 8,137
z-score
3.67
Position in the IQ distribution (mean 100, SD 15)
Measurement error: the realistic range of an IQ of 155
IQ scores always carry measurement error: the same person can score a few points higher or lower on a different day. A result of 155 is therefore best read not as an exact value but as somewhere around IQ 150–160 (±5). Under the normal-distribution model (mean 100, SD 15), that range corresponds to roughly the top 0.04% to the top 0.003% of the population.
Does 5 points matter? IQ 150 / 155 / 160 compared
| IQ | Top % | Rarity |
|---|---|---|
| IQ150 | 0.04% | 1 in 2,330 |
| IQ155this page | 0.01% | 1 in 8,137 |
| IQ160 | 0.003% | 1 in 31,560 |
A 5-point gap is within the typical measurement error of an IQ test: two people 5 points apart could easily swap places on a retest. Small differences between nearby scores should not be over-interpreted.
Characteristics and tendencies of an IQ of 155
The following are general tendencies seen at this level; individual differences apply. IQ measures one aspect of thinking, such as fluid reasoning.
- •An extremely rare level, with a tendency to quickly structure highly abstract and novel problems.
- •Even on tasks where multiple rules apply at once, such individuals often discover and apply the rules quickly.
- •At the same time, it is important to note that this is separate from interpersonal and practical skills, effort, and environment.
Relationship to Mensa
Mensa's admission criterion is "the top 2% (roughly IQ 130 or above)." An IQ of 155 may meet this criterion. Actual membership requires taking an approved supervised test.
Note: Most celebrity IQ figures seen online are estimates from unreliable sources. This page does not publish individual IQ values that cannot be verified.
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Measure your IQ for free →Frequently asked questions
- What percentile is an IQ of 155?
- An IQ of 155 corresponds to roughly the top 0.01%, or about 1 in 8,137 people.
- Is an IQ of 155 high? Is it impressive?
- It is at the Genius level level (Top ~0.1%), placing it in roughly the top 0.01%. That said, IQ measures only a small part of thinking and does not determine a person's worth or success.
- Can you join Mensa with an IQ of 155?
- Mensa's admission criterion is "the top 2% (roughly IQ 130 or above)." An IQ of 155 may meet this criterion (actual membership requires taking an approved certification test).
- What is the deviation score for an IQ of 155?
- Converting IQ (mean 100, SD 15) to a deviation score gives about 86.7.
Common questions in the IQ 145+ band
- Can a test even measure an IQ of 155 accurately?
- With difficulty. At 155 — around 1 in 8,137 people — most tests run into a ceiling: there are too few equally-able test-takers to calibrate against, and too few very hard items. Scores this high should be read as "far above the test's comfortable range" rather than a precise value.
- Does an IQ of 155 mean genius?
- The label "genius level" is sometimes attached to 145+ because it is so rare (top 0.01%). But historically, "genius" describes extraordinary achievement, which requires sustained work, opportunity, and creativity — things no IQ score measures. A very high score indicates strong reasoning capacity, nothing more and nothing less.
- Is Mensa easy with an IQ of 155?
- Mensa's cutoff is about IQ 130 (top 2%), so 155 is well above it — some higher-cutoff societies exist for the top 0.1% and beyond. That said, admission always depends on a supervised, accredited test, not on an online estimate.
Age and testing conditions
- •IQ is a deviation score relative to people of the same age: a score compares you with your own age group, so children's and adults' scores are not on the same footing.
- •Results from informal online tests, including the test on this site, are estimates. For medical or educational decisions, use a standardized test administered by a qualified professional.
- •Sleep deprivation, fatigue, and practice effects all move measured scores. Read any single result, high or low, with that in mind.