What does an IQ of 128 mean?

An IQ of 128 is classified as Very high intelligence. It is higher than 97% of people — roughly 1 in 32.

Higher than 97%
How rare 1 in 32
From the average +1.87
Classification Very high intelligence

IQ scores follow a bell curve centred on 100, with a standard deviation of 15. About 68% of people score between 85 and 115, and about 95% between 70 and 130.

What it means in practice

Mensa admits the top 2% — about IQ 130 on a test with a standard deviation of 15. A score of 128 is 2 points below that line.

Mensa practice test →

No test measures IQ exactly. A typical standard error is about 5 points, so a result of 128 really means "somewhere between 123 and 133" — and a second test on another day can land anywhere in that range.

For a child the number compares them with others of the same age, not with adults. IQ scores are age-normed, so a 10-year-old and a 40-year-old with the same score are each equally far ahead of their own age group.

Nearby scores

125 126 127 129 130 131

IQ chart: the IQ scale from 70 to 145 →

Frequently asked questions

Is an IQ of 128 good?

An IQ of 128 falls in the "Very high intelligence" range and is higher than 97% of people. Any single test is an estimate, so treat it as a range rather than an exact figure.

What percentile is an IQ of 128?

An IQ of 128 sits at about the 97 percentile, which means roughly 1 in 32 people score at least this high.

Learn about IQ

What Is the Average IQ? The Number 100 Explained Why the average IQ is always 100, what the normal range looks like, and what average really means. What Is a Good IQ Score? IQ Percentiles & the Bell Curve Explained How to read IQ scores: the bell curve, the average of 100, and what percentiles actually tell you. What IQ Do You Need for Mensa? The 98th-Percentile Threshold The exact threshold for Mensa — the 98th percentile — and what IQ number that works out to on each scale.

Curious where you would land? Take the free 60-question test and find out.