— IQ score explained

IQ of 128 — meaning, percentile & profile

An IQ of 128 is in the superior range — higher than 97% of adults. This is a genuinely strong result.

What does IQ 128 mean in practice?

An IQ of 128 means your raw performance on a standardised IQ test places you at the 97th percentile of the general adult population — higher than 97% of people. People at this level typically find abstract reasoning, pattern-matching, and learning new skills comes naturally.

IQ 128 and the normal distribution

IQ is defined with a mean of 100 and a standard deviation of 15. An IQ of 128 is 1.87 standard deviations above the mean. The normal distribution tells us that:

• About 68% of people score between 85 and 115
• About 95% of people score between 70 and 130
• About 99.7% of people score between 55 and 145
• An IQ of 128 is higher than 97% of the adult population

IQ 128 and career outcomes

An IQ of 128 is high enough to pursue any professional career. Research scientists, physicians, and academic lawyers average IQs of 125-132. At this level, the main differentiators are conscientiousness, motivation, and specific domain knowledge — not cognitive ceiling.

Comparing IQ 128 to common benchmarks

How to accurately measure your IQ

A reliable IQ test uses Item Response Theory (IRT) scoring, which adapts the scoring based on item difficulty parameters rather than simply counting correct answers. Core Brain uses IRT 3PL (three-parameter logistic) scoring — the same statistical framework used by the WAIS and Stanford-Binet — and returns your score with a 95% confidence interval so you know the measurement uncertainty.

Related IQ scores

• IQ 115 — High average, 84th percentile
• IQ 117 — High average, 87th percentile
• IQ 120 — Superior intelligence, 91th percentile
• IQ 122 — Superior intelligence, 93th percentile
• IQ 125 — Superior intelligence, 95th percentile

Related reading

• Full IQ-to-percentile reference chart
• What is the average IQ?
• IQ test types compared
• Mensa IQ score requirement