The IQ Scale: Ranges & Classifications
IQ scores follow a normal distribution with a mean of 100 and a standard deviation of 15. Here is every Wechsler classification range, how common it is, and what it means in practice. For a single score, try the percentile calculator or the IQ score chart.
The Full Intelligence Spectrum
From below 70 to 130+. Hover any band to see its name.
The 7 Wechsler IQ Classification Ranges
Shares and percentiles are for a normal distribution with mean 100 and SD 15:
Very Superior
Two or more standard deviations above the mean. Typically associated with fast learning of abstract material and strong performance on complex novel problems. The usual cutoff for high-IQ societies such as Mensa.
Superior
Well above the population average. Usually associated with comfortable handling of demanding academic material and multi-step analytical problems.
High Average
Above average. Reasoning and learning tend to be quicker than most people's, particularly on structured problem-solving tasks.
Average
The middle half of the population. A score here reflects typical reasoning ability for everyday study, work and problem-solving.
Low Average
Somewhat below average. Many people in this range benefit from extra time, structured repetition and concrete examples when learning new material.
Borderline
Well below average. Learning support or accommodations are often helpful. A single score, especially from an online test, should not be used to draw conclusions.
Extremely Low
More than two standard deviations below the mean. Only a qualified professional can assess intellectual disability, which also requires evaluating adaptive functioning, not just a test score.
The 68–95–99.7 Empirical Rule
Because the IQ scale is grounded in standard deviations, the population distributes according to exact mathematical laws:
IQ 85 to 115
About two-thirds of people score within 15 points of the mean. Note that this ±1 SD band (85–115) is wider than the Wechsler “Average” label (90–109).
IQ 70 to 130
Over 19 out of every 20 people fall within this interval. Only about 2.3% score above 130, and about 2.3% score below 70.
IQ 55 to 145
Virtually the entire population fits within this boundary. Scores above 145 make up roughly the top 0.1%.
What IQ Ranges Mean in Practice
A number like 115 or 85 is a comparison with other people on one kind of test, not a verdict on a person. Some context for reading any score:
"Average" is not "ordinary"
A score of 100 means your performance was in the middle of the norm group: half of people score higher and half lower. The 75–125 range covers roughly 90% of the population, so scores outside it are genuinely unusual in either direction.
Above 130
Higher than about 98% of people and the usual Mensa threshold (see Mensa requirements). Very high scorers often find abstract reasoning easy, but that doesn't guarantee achievement or wellbeing; gifted children in particular can develop unevenly, with reasoning far ahead of their emotional age.
Below 85
Environment matters: poor nutrition, limited schooling, stress and unfamiliarity with tests can all pull scores down. Many people with below-average scores live independent, successful lives. A low result on an online test, including ours, is not a diagnosis.
The "IQ by profession" myth
Tables claiming that doctors average 125 or other jobs average 90 are largely unverified or outdated. More complex jobs do tend to have higher average scores, but the range within every profession is huge, and effort and interest matter a great deal.
What an online estimate means
Our test reports an estimate across 5 domains using a normal-distribution model rather than a clinical norm sample, and it doesn't include processing-speed or working-memory subtests. A single sitting can vary by 10 points or more with mood, fatigue and environment, so treat it as a starting point. See our methodology.
Common Questions About the IQ Scale
What is considered a "good" IQ score on the standardized scale?
An IQ of 100 is the definition of average, and about 68% of people score between 85 and 115 (±1 SD). On the Wechsler scale, 90–109 is "Average", 110–119 "High Average", 120–129 "Superior" and 130+ "Very Superior".
What score is required to join Mensa or other high-IQ societies?
Mensa requires a score at or above the 98th percentile on an approved, supervised IQ test. On the Wechsler scale (SD 15), that corresponds to an IQ of 130 or higher.
Can practicing test questions raise my score on the IQ scale?
Practice usually improves scores on similar items, because you learn the rule types and feel less anxious. Researchers call this the practice effect; it reflects familiarity more than a change in underlying ability, which is why retests use different question sets.
Why do different tests report different IQ scales?
Most modern tests (the Wechsler scales, including the WAIS-IV, and our test) use a mean of 100 and a standard deviation of 15. The older Stanford-Binet Form L-M used an SD of 16, and the Cattell Culture Fair test uses an SD of 24. A 130 on an SD-15 test is equivalent to 132 on an SD-16 test and 148 on an SD-24 test.