IQ scale: IQ score chart, ranges and percentiles
IQ scores sit on a scale with an average of 100 and a standard deviation of 15. About 68% of people score between 85 and 115, and about 95% between 70 and 130. Use the calculator and charts below to see what any IQ score means, which percentile it falls in and how rare it is.
IQ percentile calculator
Enter an IQ score to see its percentile, how rare it is and how tests classify it. Or type a percentile to get the matching IQ.
For example 98 for the top 2%.
- Percentile
- 98th
- Higher than
- 97.7%
- People scoring higher
- 1 in 44
- Classification (WISC-V)
- Extremely High
The IQ bell curve
IQ scores follow a normal distribution: most people cluster around 100, and scores get rarer the further they are from the middle. Each step of 15 points is one standard deviation (SD).
IQ score chart: ranges and classifications
Test publishers group scores into named ranges. The labels below are the ones used on the WISC-V; the WAIS-IV labels are still widely quoted, and the WAIS-5 (2024) uses similar bands with slightly different wording such as "Above average".
| IQ range | WISC-V label | WAIS-IV label | Share of people |
|---|---|---|---|
| 130 and above | Extremely High | Very Superior | 2.3% |
| 120–129 | Very High | Superior | 6.8% |
| 110–119 | High Average | High Average | 16.1% |
| 90–109 | Average | Average | 49.5% |
| 80–89 | Low Average | Low Average | 16.1% |
| 70–79 | Very Low | Borderline | 6.8% |
| 69 and below | Extremely Low | Extremely Low | 2.3% |
Shares come from a normal distribution with mean 100 and SD 15 and are rounded.
IQ percentile chart
The percentile tells you what share of people score lower than you. Rarity counts people scoring higher for scores of 100 and above, and people scoring lower below 100. Pick any score for a full explanation.
| IQ score | Percentile | Higher than | Rarity |
|---|---|---|---|
| 55 | 0.13th | 0.13% | 1 in 741 |
| 60 | 0.38th | 0.38% | 1 in 261 |
| 65 | 1st | 0.98% | 1 in 102 |
| 70 | 2nd | 2.3% | 1 in 44 |
| 75 | 5th | 4.8% | 1 in 21 |
| 80 | 9th | 9.1% | 1 in 11 |
| 85 | 16th | 15.9% | 1 in 6.3 |
| 90 | 25th | 25.2% | 1 in 4 |
| 95 | 37th | 36.9% | 1 in 2.7 |
| 100 | 50th | 50% | 1 in 2 |
| 105 | 63rd | 63.1% | 1 in 2.7 |
| 110 | 75th | 74.8% | 1 in 4 |
| 115 | 84th | 84.1% | 1 in 6.3 |
| 120 | 91st | 90.9% | 1 in 11 |
| 125 | 95th | 95.2% | 1 in 21 |
| 130 | 98th | 97.7% | 1 in 44 |
| 135 | 99th | 99.02% | 1 in 102 |
| 140 | 99.62th | 99.62% | 1 in 261 |
| 145 | 99.87th | 99.87% | 1 in 741 |
| 150 | 99.957th | 99.957% | 1 in 2,330 |
| 155 | 99.988th | 99.988% | 1 in 8,140 |
| 160 | 99.9968th | 99.9968% | 1 in 31,600 |
| 170 | 99.99985th | 99.99985% | 1 in 653,000 |
| 180 | > 99.9999th | > 99.9999% | 1 in 20.7 million |
| 190 | > 99.9999th | > 99.9999% | 1 in 1.01 billion |
| 200 | > 99.9999th | > 99.9999% | 1 in 76.4 billion |
How the IQ scale works
Modern IQ tests report a deviation IQ. Your answers are scored and compared with a large norming sample of people your age, then converted to a scale where the average is 100 and the standard deviation is 15. A score of 115 is one standard deviation above the average; 130 is two.
That is why an IQ score is really a rank, not a measurement in units like centimetres. The same number of correct answers can give a different IQ at 20 and at 70, because you are compared with a different group.
The older ratio IQ worked differently. William Stern proposed dividing mental age by chronological age in 1912, Lewis Terman's 1916 Stanford-Binet multiplied it by 100 and made "IQ" popular, and David Wechsler replaced it with the deviation IQ on the Wechsler-Bellevue scale in 1939.
What is a normal IQ range?
On a scale with mean 100 and SD 15, about 68% of people score between 85 and 115, about 95% between 70 and 130, and about 99.7% between 55 and 145.
Test publishers call 90 to 109 the Average range, which holds about half of all people. When people talk about a "normal IQ", they usually mean either that band or the wider 85 to 115 range.
Why the same IQ can mean different things on different tests
Most modern tests, including the Wechsler scales and the Stanford-Binet 5, use a standard deviation of 15. The older Stanford-Binet and the Cattell Culture Fair test use 16, and the Cattell III B uses 24. The same rank therefore gets a bigger number on a wider scale.
Mensa's qualifying scores show this well. American Mensa accepts a full-scale IQ of 130 on the Wechsler scales or the Stanford-Binet 5, 132 on the older Stanford-Binet and 148 on the Cattell. All of them are roughly the top 2%. The calculator above converts between these scales.
What an IQ score can and cannot tell you
No test measures IQ exactly. On individually administered tests such as the WAIS or WISC, the full-scale score comes with a 95% confidence interval of roughly ±5 points, so a 112 is best read as "probably somewhere around 107 to 117".
Standard adult and child tests top out at 160. Higher numbers need special extended norms, so most claims of 180 or 200 come from unsupervised tests or old ratio-IQ calculations.
IQ predicts some things, such as school results, on average. It does not measure creativity, character, motivation or knowledge, and only a qualified psychologist with a standardised test can make a diagnosis. Online tests, including ours, are self-assessments.
Every IQ score explained
One page per score from 55 to 160, plus the extreme scores people ask about.
IQ scale: frequently asked questions
What is the IQ scale?+
The IQ scale is the scoring system used by intelligence tests. It is set so that the average score in the population is 100 and the standard deviation is 15. Every score is therefore a position relative to other people: 115 is higher than about 84% of people, 130 higher than about 98%.
What is a normal IQ range?+
About half of all people score between 90 and 109, which tests call the Average range. About 68% score between 85 and 115 and about 95% between 70 and 130.
What IQ score is considered genius?+
"Genius" is not a scientific or clinical category, and no modern test uses it. The WISC-V calls 130 and above Extremely High, and the Stanford-Binet 5 calls 145 and above "very gifted or highly advanced". Popular articles often use 140 or 145 as an informal genius line.
What is the highest possible IQ score?+
Standard norms for the WAIS-IV and WISC-V go up to 160, which is four standard deviations above the mean, or about 1 in 31,600 people. Pearson's extended WISC-V norms for very gifted children reach 210. Statistically, 200 would be about 1 in 76 billion, more than the number of people alive, which is why such claims cannot be checked against a norming sample.
How is an IQ percentile calculated?+
Because IQ scores follow a normal distribution, the percentile is the share of the distribution below your score. Subtract 100, divide by the standard deviation (15) to get a z-score, then look up the normal curve: z = 2 (IQ 130) gives about 97.7%, z = 1 (IQ 115) about 84.1%.
How accurate is an IQ score?+
A professionally administered test is reliable to within a few points: a 95% confidence interval of about ±5 points is typical. Your score can still shift between tests and over time, and online tests are less controlled than a one-to-one assessment with a psychologist.