Why is 100 the average?

IQ tests are standardized so the mean is always 100 with a standard deviation of 15, making comparison across tests possible.

What does an average IQ predict?

Average IQ (90-110) predicts adequate performance in most educational and occupational settings for typical individuals.

No. Average IQ indicates cognitive abilities sufficient for most life tasks. Intelligence is contextual and multidimensional.

Approximately 2-3% score exactly 100, as IQ is a continuous variable with most clustering around the mean.

Peter Kolomiets

|March 23, 2026|Updated Apr 13, 2026|5 min read

Ready to discover your Iq Test?

Wechsler, D.. Wechsler, D. (2008). WAIS-IV Administration and Scoring Manual
Jensen, A. R.. Jensen, A. R. (1998). The g Factor: The Science of Mental Ability
Kaufman, A. S.. Kaufman, A. S. (2009). IQ Testing 101

Put what you've learned into practice with these free assessments:

IQ scores follow a normal distribution with mean 100 and standard deviation 15. Learn how to interpret your position on the bell curve.

IQ correlates moderately-to-strongly with school grades and standardized test scores, explaining 25-50% of academic performance variance.