Average
The middle two-thirds of the population sit in this range.
What this band represents
The average band — 90 to 109 — captures roughly half of all adults. By construction, an IQ of 100 is the population median: half of all test-takers score above 100 and half score below. Most professional careers and academic programs are accessible to anyone in this range, especially when paired with strong work habits and domain expertise. The popular framing of '100 = average' undersells the practical breadth of this band: a 90 and a 109 differ by more than a full standard deviation but are both correctly described as 'average'.
Important context
When you see headlines about 'national IQ' or 'average IQ by country', the underlying data almost always live somewhere in this band. Differences between national means rarely exceed 5–10 points and are confounded by test access, education, nutrition, and language. Within-group variability dwarfs between-group variability for every well-studied population.
A note of caution. If you scored exactly at 100, you are at the literal center of the human distribution — that is not a result that deserves any concern.
How this band sits in the population
- Score range: 90–109
- Percentile range: 25th–74th percentile
- Population frequency: Roughly 50% of the population
- z-score range: z -0.67 to 0.60
Frequently asked questions about this band
- What is a "good" IQ score?
- How accurate are online IQ tests?
- Can IQ be improved with practice?
- Why did I get different scores on different IQ tests?