IQ 90: what it means, percentile and how rare it is

An IQ score of 90 is higher than about 25.2% of people, which puts it in the 25th percentile. Roughly 1 in 4 people score lower than 90. On the WISC-V it is classified as Average.

Percentile: 25th
Higher than: 25.2%
People scoring lower: 1 in 4
WISC-V classification: Average

Where an IQ of 90 falls on the bell curve. The shaded area is the 25.2% of people who score lower. (-0.67 SD)

What does an IQ of 90 mean?

90 is the lowest score in the Average range (90–109).
In a group of 100 people, about 25 would score lower than 90.

About half of all people score between 90 and 109, the Average range. 100 is the exact middle of the scale by design: tests are normed so that the average adult or child of a given age scores 100.

Within this range, differences of a few points mean very little. Once measurement error of about ±5 points is taken into account, a 96 and a 104 are effectively the same result.

An average score is not a limit. Most people in every career and walk of life score in or near this range, and knowledge, skills, effort and personality explain far more about day-to-day success than a few IQ points.

IQ 90 on other scales and tests

Different tests spread scores differently. The same rank as an IQ of 90 on an SD-15 test gives these numbers elsewhere:

Scale	Equivalent score	Classification
SD 15: WISC-V, WAIS, Stanford-Binet 5	90	Average
WAIS-IV (older label)	90	Average
Stanford-Binet 5	90	Average
SD 16: older Stanford-Binet, Cattell Culture Fair	89	–
SD 24: Cattell III B	84	–

How precise is an IQ score of 90?

No test measures IQ exactly. On individually administered tests such as the WAIS, the full-scale score comes with a 95% confidence interval of roughly ±5 points, so a result of 90 is best read as "probably somewhere between 85 and 95". Scores can also shift a few points between different tests or after a few years.

Online tests, including ours, are self-assessments. They are useful for curiosity and practice, but they are not a substitute for an assessment by a psychologist.

IQ scores near 90

IQ score	Percentile	Higher than	WISC-V classification
85	16th	15.9%	Low Average
86	18th	17.5%	Low Average
87	19th	19.3%	Low Average
88	21st	21.2%	Low Average
89	23rd	23.2%	Low Average
90	25th	25.2%	Average
91	27th	27.4%	Average
92	30th	29.7%	Average
93	32nd	32%	Average
94	34th	34.5%	Average
95	37th	36.9%	Average

Check another IQ score

IQ score

Test scale (standard deviation)

Or start from a percentile

For example 98 for the top 2%.

Percentile: 25th
Higher than: 25.2%
People scoring lower: 1 in 4
Classification (WISC-V): Average

IQ 90: frequently asked questions

Is an IQ of 90 good?+

An IQ of 90 is an average score: it is in the range where half of all people fall and it is higher than about 25.2% of people. It is a typical result, and it does not limit what you can learn or do.

What percentile is an IQ of 90?+

An IQ of 90 is in the 25th percentile on a scale with mean 100 and standard deviation 15. It is higher than about 25.2% of people and lower than about 74.8%.

How rare is an IQ of 90?+

Roughly 1 in 4 people score lower than 90. In a group of 1,000 people you would expect about 252 to score lower.

Is 90 above average?+

No, it is a little below the mean of 100, but it is still inside the Average range (90 to 109). The difference is smaller than the typical ±5-point measurement error, so in practice it is an average score.