The IQ Scale Explained: What Every Score Range Means
On modern IQ tests the average score is 100 and each 15 points is one standard deviation. About 68% of people score between 85 and 115, about 95% between 70 and 130, and only around 2% score above 130.
How the bell curve shapes IQ scores
IQ tests are normed so that results follow a bell-shaped curve. Most people cluster near the middle, and scores become steadily rarer toward either end. Because the scale is fixed β mean 100, standard deviation 15 β a score tells you where you stand relative to others your age rather than how many questions you answered.
This is also why a score of 100 is not a pass mark. It simply means you performed exactly in the middle of the reference group. The history behind this approach is covered in our article on what IQ is and where it came from.
IQ score ranges and classifications
Labels differ slightly between test publishers. The table below uses descriptions close to those in recent Wechsler manuals, with approximate population shares.
| IQ range | Common description | Approx. share | Percentile |
|---|---|---|---|
| 145 and above | Very superior / profoundly gifted | β0.1% | 99.9th+ |
| 130β144 | Very high / gifted | β2.1% | 98thβ99.9th |
| 120β129 | Superior | β6.7% | 91stβ97th |
| 110β119 | High average | β16% | 75thβ90th |
| 90β109 | Average | β50% | 25thβ73rd |
| 80β89 | Low average | β16% | 9thβ23rd |
| 70β79 | Borderline | β6.7% | 2ndβ8th |
| Below 70 | Extremely low | β2.2% | Below 2nd |
What each range tends to mean in everyday life
In the 90β109 band, people usually handle schooling and most jobs without difficulty. The 110β129 range is common among university graduates and in analytically demanding work. Above 130 β the threshold Mensa International uses, typically the top 2% β people often learn abstract material very quickly, although high scores do not guarantee success or happiness.
Scores below 70 are one part of how clinicians assess intellectual disability, but a diagnosis also requires real difficulties with daily living skills. A number alone is never enough, and a qualified psychologist should always interpret it.
Reading your own score sensibly
Every test has a margin of error, so think in ranges. A result of 112 is better read as roughly 107 to 117. Online tests, including ours, are shorter than clinical assessments, which widens that band. If you want to understand how average scores vary between groups, see our guides to average IQ by age and average IQ by profession.
Common questions
Is 120 a good IQ score?
Yes. A score of 120 sits around the 91st percentile, meaning it is higher than roughly nine in ten people of the same age. It is usually described as superior or high above average.
What IQ is considered gifted?
Most schools and societies use 130 or above, which corresponds to roughly the top 2% of the population.
What is a normal IQ?
Anything from about 85 to 115 is within the normal range, and around two-thirds of people score there.
Is 140 a genius IQ?
There is no scientific 'genius' threshold. A score of 140 is very rare β about 1 in 260 people β but genius usually refers to exceptional achievement, not a test score.
About the author
Dr. Elena Marsh β Elena has spent over a decade studying intelligence measurement and test construction, with a focus on fluid reasoning and fair item design.
Reviewed by Prof. Daniel Okafor β Daniel reviews item statistics and norming assumptions for our test and guides.
Sources and further reading
- Wechsler, D. (2008). WAIS-IV Technical and Interpretive Manual. Pearson.
- American Psychiatric Association. (2022). DSM-5-TR. Section on intellectual developmental disorder.
- Gottfredson, L. S. (1997). Why g matters. Intelligence, 24(1), 79β132.