IQ 100: what it means, percentile and how rare it is
An IQ score of 100 is the exact average: half of people score higher and half score lower, which puts it in the 50th percentile. On the WISC-V it is classified as Average.
- Percentile
- 50th
- Higher than
- 50%
- People scoring higher
- 1 in 2
- WISC-V classification
- Average
What does an IQ of 100 mean?
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 100 on other scales and tests
Different tests spread scores differently. The same rank as an IQ of 100 on an SD-15 test gives these numbers elsewhere:
| Scale | Equivalent score | Classification |
|---|---|---|
| SD 15: WISC-V, WAIS, Stanford-Binet 5 | 100 | Average |
| WAIS-IV (older label) | 100 | Average |
| Stanford-Binet 5 | 100 | Average |
| SD 16: older Stanford-Binet, Cattell Culture Fair | 100 | – |
| SD 24: Cattell III B | 100 | – |
How precise is an IQ score of 100?
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 100 is best read as "probably somewhere between 95 and 105". 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 100
Check another IQ score
For example 98 for the top 2%.
- Percentile
- 50th
- Higher than
- 50%
- People scoring higher
- 1 in 2
- Classification (WISC-V)
- Average
IQ 100: frequently asked questions
Is an IQ of 100 good?+
An IQ of 100 is an average score: it is in the range where half of all people fall and it is higher than about 50% of people. It is a typical result, and it does not limit what you can learn or do.
What percentile is an IQ of 100?+
An IQ of 100 is the 50th percentile: exactly in the middle, with half of people scoring higher and half lower.
Is 100 above average?+
No, it is exactly average. 100 is the mean of the IQ scale by design: half of people score higher and half lower.