How to read your IQ score
An IQ score is not a count of correct answers. It is a position on a distribution — which is why the same raw performance can produce different numbers on different tests.
The scale
Scores are placed on a normal distribution with a mean of 100 and a standard deviation of 15. Your number says how far you sit from the average, in standard deviations. It is a ranking, not a quantity of intelligence.
What the bands mean
- Below 85 — around 16% of people score here.
- 85 to 115 — the middle band, containing about 68% of people.
- 115 to 130 — above average, roughly the top 16%.
- 130 and above — about the top 2%, the range high-IQ societies use as a threshold.
Percentiles are clearer
'IQ 120' is abstract. 'Higher than about 91% of people' is not. Percentiles also make the shape of the distribution obvious: the gap between 100 and 110 covers far more people than the gap between 130 and 140, even though both are ten points.
The breakdown matters more than the total
Two people scoring 118 can be completely different thinkers — one strong on spatial reasoning and slow on verbal, the other the reverse. The total hides that. The per-category scores are the part you can actually use, whether you are choosing what to study or what to practise.
How much to trust one result
Any single sitting carries measurement error. Well-constructed supervised tests have a confidence interval of several points; unsupervised online tests are wider still. Treat your score as a range, not a point, and treat a series of attempts as more informative than your best one.
And keep the limits in view: the test samples a specific slice of cognition. It says nothing about creativity, judgement, persistence or how well you work with other people.