What Does an IQ of 127 Mean? Percentile, Rarity and the Gap to Mensa
An IQ of 127 is the 96.4th percentile on SD 15, about 1 in 28 people, and 3 points short of the 130 Mensa line. See 127 on each scale, how many people in a class reach it, which gifted-programme rule it misses, and how far one score can move.
An IQ of 127 is the 96.4th percentile on a scale with a mean of 100 and a standard deviation (SD) of 15: about 3.6 in 100 people score higher, or 1 in 28. It is a high score, and 3 points short of the 130 line that Mensa uses on Wechsler tests. On an SD 16 scale a 127 is the 95.4th percentile, and on SD 24 the 87.0th.
New here: the same 127 means less on other scales. It matches 125.3 on SD 15 if it came from an SD 16 test, and 116.9 if it came from an SD 24 test. In a class of 30, about 1 child scores at or above 127, and two classes in three have at least one. Below: the percentile, the scales, Mensa, gifted programmes and how far one score can be trusted.
Key takeaways
- An IQ of 127 is the 96.4th percentile on SD 15, the 95.4th on SD 16 and the 87.0th on SD 24. On the usual scale that is about 1 in 28 people.
- No test on American Mensa’s list has a 127 line. The lowest lines are 130, so a 127 is 3 points short on a Wechsler test and 5 short on a CogAT.
- One district’s published rule gives automatic gifted eligibility at two standard deviations above the mean. That is 130 on SD 15, so 127 does not meet it.
- In a school of 1,000 children drawn from the norm group, about 36 would score 127 or higher. In a class of 30, about 1.
- A single score is a range. With a margin of 5 points either side, a 127 could sit anywhere from 122 to 132.
What does an IQ of 127 mean?
It means you scored 27 points above the average of 100, or 1.8 standard deviations. That is the IQ of 127 compared to average. That puts you above about 96 of every 100 people in the norm group. A norm group is the large sample of people a test was scored against. Your 127 says where you stand in that group, and nothing more.
It is a high score, but not a rare one. That is the whole IQ 127 meaning. By itself it is not a diagnosis, a label or a promise about your future. Our IQ classifications guide shows the labels publishers attach to each band of scores.
What percentile is an IQ of 127?
An IQ of 127 is the 96.4th percentile on SD 15. About 3.6% of people score higher, or 1 in 28. The 127 IQ percentile is our own arithmetic on a normal curve. It holds only if the test’s norm group is close to normal. Our IQ percentile calculator gives the same answer for any score, and the IQ bell curve shows where 127 sits.
| IQ score | Percentile | Share who score higher | About 1 in |
|---|---|---|---|
| 125 | 95.2% | 4.8% | 1 in 20 |
| 126 | 95.8% | 4.2% | 1 in 24 |
| 127 | 96.4% | 3.6% | 1 in 27 |
| 128 | 96.9% | 3.1% | 1 in 32 |
| 129 | 97.3% | 2.7% | 1 in 37 |
| 130 | 97.7% | 2.3% | 1 in 44 |
One point near 127 is worth about half a percentile point. That is why a 127 and a 128 are close neighbours, and why the exact score matters less than the scale it came from.
Is an IQ of 127 the same on every scale?
No. Scales share a mean of 100 but not an SD: 15 on Wechsler tests, 16 on older Stanford-Binet forms and the CogAT, and 24 on Cattell tests. The same 127 sits at a different percentile on each. Our report on SD 15 vs 16 explains why.
| Scale | Where 127 sits | Percentile of a 127 | About 1 in | Same standing on SD 15 |
|---|---|---|---|---|
| SD 15 (Wechsler) | 1.80 SDs above average | 96.4th | 1 in 28 | 127.0 |
| SD 16 (older Stanford-Binet, CogAT) | 1.69 SDs above | 95.4th | 1 in 22 | 125.3 |
| SD 24 (Cattell) | 1.13 SDs above | 87.0th | 1 in 8 | 116.9 |
So check the scale before you compare. A 127 on SD 24 is a far weaker result than a 127 on SD 15. Going the other way, the 96.4th percentile reads 128.8 on SD 16 and 143.2 on SD 24. Our IQ score converter moves a score from one scale to another.
Is an IQ of 127 good, and is it genius?
Yes, 127 is a good IQ. It is higher than about 96 in 100 people in the norm group. It is not genius by any agreed line, because no agreed line exists. Our guide on whether an IQ of 130 is genius sets out the claims people make about the top few percent.
Whether 127 is good enough depends on the cut-off you face. For some purposes it clears the bar, and for others it falls just short. The next two sections cover the two lines people ask about most.
Can you join Mensa with an IQ of 127?
No. Mensa asks for the 98th percentile on a supervised test, and 127 is the 96.4th. American Mensa’s qualifying-scores page, which we read on 14 November 2026, lists no test with a 127 line.
Its lowest IQ lines are 130, for the Wechsler scales, the Stanford-Binet 5, the DAS-II and the RIAS. The Woodcock-Johnson IV line is 131, the CogAT and OLSAT lines are 132, and the Cattell line is 148. On SD 15 the exact 98th percentile is 130.8, so a 127 is 3.8 points short. Our Mensa IQ requirements guide gives the test-by-test table, and our post on an IQ of 128 covers the score one point above.
Practice and retesting can move a score by a few points. Our Mensa test preparation guide covers how much, and what Mensa allows.
Which gifted-programme cut-offs does an IQ of 127 clear?
It depends on the district, and no national line exists. One published rule, from Andalusia City Schools in Alabama, gives automatic eligibility when a full-scale or composite IQ on an individually given test is two standard deviations above the mean or higher.
Two standard deviations above the mean is 130 on SD 15 and 132 on SD 16. A 127 does not meet that rule on either scale. The same page lists a second route, a matrix of multiple criteria set by the State Department of Education, which asks for information on aptitude, performance and characteristics. We read that one page on 14 November 2026. Other districts set other lines, so ask yours which test and which scale it uses.
Where would your own score land?
Take the IIF-certified assessment and get your score with the scale it was measured on, the percentile it corresponds to and the confidence range around it — the three figures most online tests leave out.
Find your IQ score now! →How rare is an IQ of 127 in a classroom of 30?
About 1 child in 28 scores at or above 127, so a class of 30 has one on average. The chance that a class of 30 holds at least one is 67%, or about 2 classes in 3.
| Group size | Expected to score 127 or higher |
|---|---|
| A class of 30 | 1.1 |
| 100 people | 3.6 |
| A lecture hall of 300 | 11 |
| A school of 1,000 | 36 |
| A town of 10,000 | 359 |
These counts assume a random draw. A real class is not one: a selective school or a gifted programme will hold more, and the counts say nothing about any one child.
How accurate is a single score of 127?
Not very. Our report on the IQ margin of error says a well-normed adult test on SD 15 typically has a standard error of 2 to 3 points. That is about 5 to 6 points either side at 95% confidence. We took the figure from that report, not from a test manual.
Apply 5 points to a 127 and the range runs from 122 to 132. That is the 92.9th to the 98.4th percentile, and the top of it passes the Mensa line. So one sitting at 127 cannot tell you whether your level is above or below 130. Our IQ test accuracy page shows how the margin is calculated, and our post on an IQ of 129 works through what it does to a score one point from the line.
How does an IQ of 127 compare with 125, 128 and 131?
A 127 is 2 points above a 125 (the 95.2nd percentile) and 1 point below a 128 (the 96.9th). It is 4 points under a 131 (the 98.1st). The steps are small. Read our pages on an IQ of 125 and an IQ of 131 for each neighbour.
What does a 127 on an online test mean?
Treat it as a rough guide. Online tests use their own norm groups, and many do not say which SD they use. A 127 IQ score from a website is not the same as a 127 from a supervised test with a trained examiner. If you got 127 on one site and 119 on another, that spread is normal.
For a score of your own, take the IQ test, then place the result with the percentile calculator and the converter above.
Quick answers
- What is an IQ of 127? The 96.4th percentile on SD 15, about 1 in 28 people. On SD 16 it is the 95.4th, and on SD 24 the 87.0th.
- Is 127 IQ good? Yes. It is higher than about 96 in 100 people, and 3 points under the 130 Mensa line.
- Can you join Mensa with 127? No. American Mensa’s list has no 127 line, and its lowest IQ lines are 130.
- Is an IQ of 127 genius? There is no agreed genius line. A 127 is a high score, not a label.
- How rare is 127? About 1 in 28, so a class of 30 has about one.
Sources
- American Mensa. Qualifying test scores (page read 14 November 2026).
- Andalusia City Schools, Alabama. Gifted services: evaluation and eligibility (page read 14 November 2026).
- IQ Metrics. An IQ score is a range, not a number: the margin of error (2 September 2026).
- IQ Metrics. IQ test accuracy: reliability, SEM and limits.
- Percentiles, 1-in-N figures, the 130.8 cut-off and the scale conversions on this page are our arithmetic on a normal curve with mean 100; they are not published test norms.
Keep reading
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Scores & ScalesWhat Does an IQ of 128 Mean?
An IQ of 128 is the 96.9th percentile on SD 15, about 1 in 32 people, and 2 points under the usual 130 Mensa line. See what 128 means on SD 16 and SD 24, why no test on American Mensa's list takes it, how far one sitting can move the score, and which famous people sit near it.
Scores & ScalesMensa IQ Score Requirements
Mensa admits the top 2% of scorers, but "the top 2%" is a rank, not a number, and the number it maps to changes with the test you sat. Here is what qualifies on the Wechsler, Stanford-Binet and Cattell scales, the two routes to membership, and what the supervised admission test is actually like.
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An IQ of 129 is the 97.3rd percentile, about 1 in 38, on SD 15. One point under 130 is smaller than the error in one score: a true 129 reads 130 or more about 4 sittings in 10. See the scales, the Mensa lines and the arithmetic behind that claim.