IQ 90: percentile and Average range

IQ 90 is at percentile 25.2: a quarter of people score at or below it. It is the lower edge of the Average band, which runs from 90 to 109.

IQ 90 in numbers

Percentileof people score at or below	25.2
Rarityat or below	1 in 4.0
Commonly used band90 to 109	Average

Band labels are the commonly used WISC-V ones, as listed by Smart Kids with Learning Disabilities: Understanding IQ Test Scores. Labels are conventions in common use; each test publisher words its own.

Where it sits on the curve

Shaded: the people who score at or below it (25.2%).

The same position on other scales

Same percentile on every row; the number changes because the scales use different standard deviations.

Scale	Score	Percentile
SD 15	90	25.2
SD 16	89	25.2
SD 24	84	25.2

How many people score at or below 90?

At IQ 90, 25.2 percent of people score at or below the score, or one in 4.0 people. The other 74.8 percent score above it.

A percentile shows a score’s position in the group used to norm a test. It does not show how many questions someone answered correctly. To try other values, type them into the percentile tool; a 90 from one test and a 90 from another only match when both tests spread scores alike.

Why are 90 and 109 both Average?

Scores 90 and 109 share the Average label because both fall within the band from 90 to 109. The lower edge is just below the mean, while the upper edge is above it.

IQ 90 is 0.7 standard deviations below the mean. The same position corresponds to 89 on an SD 16 scale and 84 on an SD 24 scale.

What does the Average label tell you?

A word like Average sorts a number into a wide bin; it says nothing about a person's strengths, interests or school record. It also does not explain performance on a particular task or replace the details in a test report.

IQ scores come from normed tests that compare performance with a reference group. IQClock’s timed reasoning test reports correct answers and a level, not an IQ score. Browse all IQ scores for context on nearby score pages.

Questions

Is IQ 90 below average?

IQ 90 is below the mean of 100, but it falls within the Average band. The score’s position relative to the mean and its band label describe different things: one gives a location, while the other groups a range of scores.

What percentile is IQ 90?

IQ 90 is at percentile 25.2 in the figures used here. That means 25.2 percent score at or below it and 74.8 percent score above it.

Does IQ 90 mean the same thing on every test?

The number alone may not have the same position across tests because the scales can use different standard deviations. Check the test name and scale when interpreting a reported score.