How to use the calculator
Choose a direction, type a number and pick the scale your test uses. Almost all modern tests, including the WAIS, the WISC and the current Stanford-Binet, use a standard deviation of 15. Older Stanford-Binet editions used 16, and the Cattell III B, used by British Mensa, uses 24. If you are not sure, choose 15.
What an IQ percentile means
A percentile is the share of people your age who score below you. At the 91st percentile you scored higher than about 91 in 100 people. Percentiles compare better than IQ numbers, because the same rank carries different numbers on different tests.
IQ to percentile table
Every five points from 55 to 160 on the standard scale. Rarity counts people at that score or higher above 100, and at that score or lower below 100.
| IQ | Percentile | How rare | Level |
|---|---|---|---|
| 160 | 99.997 | 1 in 31,574 | Very Superior |
| 155 | 99.99 | 1 in 8,139 | Very Superior |
| 150 | 99.96 | 1 in 2,331 | Very Superior |
| 145 | 99.87 | 1 in 741 | Very Superior |
| 140 | 99.62 | 1 in 261 | Very Superior |
| 135 | 99th | 1 in 102 | Very Superior |
| 130 | 98th | 1 in 44 | Very Superior |
| 125 | 95th | 1 in 21 | Superior |
| 120 | 91st | 1 in 11 | Superior |
| 115 | 84th | 1 in 6.3 | High Average |
| 110 | 75th | 1 in 4.0 | High Average |
| 105 | 63rd | 1 in 2.7 | Average |
| 100 | 50th | 1 in 2.0 | Average |
| 95 | 37th | 1 in 2.7 | Average |
| 90 | 25th | 1 in 4.0 | Average |
| 85 | 16th | 1 in 6.3 | Low Average |
| 80 | 9th | 1 in 11 | Low Average |
| 75 | 5th | 1 in 21 | Borderline |
| 70 | 2nd | 1 in 44 | Borderline |
| 65 | 0.98 | 1 in 102 | Extremely Low |
| 60 | 0.38 | 1 in 261 | Extremely Low |
| 55 | 0.13 | 1 in 741 | Extremely Low |
How the calculation works
IQ scores are designed to follow a normal distribution with a mean of 100. The calculator turns your score into a z-score, the number of standard deviations it sits from 100, and reads the share of the curve below that point. Going the other way, it finds the z-score for a percentile and converts it back to IQ points on the scale you chose. These are the same steps used to build the IQ score range chart.
A percentile describes rank, not precision: every measured score has a margin of error.
Frequently asked questions
What percentile is an IQ of 130?
About the 98th percentile on a test with a standard deviation of 15: higher than about 98 in 100 people, roughly 1 in 44.
What IQ is the 99th percentile?
About 135 on a standard-deviation-15 test, about 137 on a 16 test and about 156 on the Cattell scale with 24.
What does percentile mean for IQ?
A percentile is the share of people who score below you. At the 75th percentile you scored higher than about 75 in 100 people of your age.
Why does my score look different on another test?
Tests spread scores differently. The same rank is about 130 on a standard-deviation-15 test but about 148 on the Cattell scale, so always compare percentiles, not raw IQ numbers.
How is the percentile calculated?
IQ scores follow a normal (bell-shaped) distribution. The calculator turns your score into a z-score, the number of standard deviations from 100, and reads the share of the curve below it.
Ready for the real thing?
32 puzzles, 25 minutes, your score and its range straight away.
Start the free test