What does an IQ of 155 mean?
An IQ of 155 sits at the far right tail of the distribution — above 145, in the range popularly called "genius." Scoring higher than about 100% of people, 155 is extraordinarily uncommon, and it's worth being clear-eyed about what such a number does and doesn't say.
- Classification
- Highly Gifted
- Percentile
- >99th
- Scores higher than
- 100% of people
- Rarity
- about 1 in 8100
- vs. average (100)
- +55 points
Key takeaways
- An IQ of 155 is in the Highly Gifted range (145+), popularly called "genius."
- It is about the >99th percentile — about 1 in 8100.
- "Genius" is a popular label, not a clinical category.
Looking for the in-depth guide for this range? See what an IQ of 150 means.
Is an IQ of 155 good?
By the numbers, an IQ of 155 is exceptional — the kind of score only a tiny fraction of people reach. But "genius" is a loose popular term, not a scientific category, and at these extremes a short online test is least precise. Treat 155 as a sign of very strong reasoning, not a verdict on a person; achievement at this level still depends on what someone actually does.
How rare is an IQ of 155?
An IQ of 155 is extremely rare — about 1 in 8100. Fewer than under 0.1% of people reach it; in a random group of 1,000 you would expect at most about 1. Scores this far out also carry the widest measurement error.
What an IQ of 155 looks like in practice
At this extreme, score differences become hard to measure reliably and tell you little about any individual. Reasoning power is abundant; what shapes outcomes is how it's applied.
IQ 155 compared to nearby scores
No short test pins ability to a single point. An IQ of 155 is best read as the centre of a range — roughly 151 to 159 — rather than an exact value, and it is not meaningfully different from scores a few points either side. When you compare two people, overlapping ranges matter more than the point scores.
Where 155 sits on the IQ scale
| IQ Range | Classification | % of People | What it means |
|---|---|---|---|
| ≤69 | Extremely Low | ~2.2% | Well below average. On clinical tests this range may warrant professional assessment. |
| 70–79 | Borderline | ~6.7% | Below average reasoning on this scale. |
| 80–89 | Low Average | ~16.1% | Slightly below the population average. |
| 90–109 | Average | ~50% | The middle of the distribution — where most people score. |
| 110–119 | High Average | ~16.1% | Above average reasoning ability. |
| 120–129 | Superior | ~6.7% | Notably above average — roughly the top 10%. |
| 130–144 | Gifted | ~2.1% | The conventional 'gifted' threshold (130) and above — top ~2%. Mensa qualifies here. |
| 145+ | Highly Gifted | ~0.1% | Exceptionally rare — the far right tail of the distribution. |
Frequently asked questions
Is an IQ of 155 good?+
By the numbers an IQ of 155 is exceptional — well into the top fraction of a percent. Bear in mind that "genius" is a popular label rather than a clinical one, and online tests are least accurate at these extremes.
What percentile is an IQ of 155?+
An IQ of 155 is about the >99th percentile on the standard mean-100, SD-15 scale — meaning you score higher than roughly 100% of people.
How rare is an IQ of 155?+
A score of 155 is about 1 in 8100, based on the normal distribution of IQ in the population.
Does an IQ of 155 qualify for Mensa?+
Yes — Mensa admits people who score at or above the 98th percentile, and an IQ of 155 clears that bar on the SD-15 scale. You still need to qualify on a Mensa-approved or supervised test, not an online estimate.
Related guides
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