IQ Score Ranges Explained: What the Numbers Mean

IQ scores are positioned on a bell curve with a mean of 100 and a standard deviation of 15. About 68% of people score within one standard deviation of the mean (85–115), and about 95% within two (70–130).

Scores from 90 to 109 are typically described as average. Scores from 110 to 119 are high average, 120 to 129 superior, and 130 and above often described as very superior. Below 80, ranges describe below-average to very low performance. These labels describe relative position on the curve, not a person's worth or fixed capacity.

An average score simply means performance near the middle of the reference distribution — the most common outcome by definition. There is nothing limiting about being average; it describes the majority of test-takers.

Every test result carries measurement error. A single sitting produces a point estimate plus a confidence interval — a range within which the true score likely falls. Two slightly different scores from repeated testing are normal and expected.