IQ Score Chart

The full IQ score range chart

This is the standard deviation IQ scale used across most modern intelligence tests (mean 100, standard deviation 15), including the transparent scoring model used on our own IQ test and Mensa-style practice test. The descriptive band names below follow the general convention used across published psychometric literature, not any single proprietary test.

Those percentages come directly from the mathematics of a normal distribution with mean 100 and standard deviation 15, they are not specific to any one test. Roughly 68% of the population falls within one standard deviation of average (85 to 115), and roughly 95% falls within two standard deviations (70 to 130), which is why scores much outside that middle range are, by definition, uncommon.

What is a percentile, and how is it different from an IQ score?

An IQ score and a percentile describe the same underlying result in two different ways. The IQ score tells you where you land on the standardized 100-point-average scale. The percentile tells you what share of a comparison population scored at or below you. For example, an IQ score of 115 corresponds to roughly the 84th percentile, meaning an estimated 84% of people would score at or below that on a comparably normed test, not that you answered 84% of questions correctly (those are two completely different numbers that happen to look similar). Our own IQ test and Mensa-style test both show an approximate percentile alongside your estimated IQ for exactly this reason: the percentile is often the more intuitive way to understand where a result sits relative to others.

What counts as "genius-level" IQ?

There is no single official, universally agreed threshold for the word "genius" in psychometrics, it is a popular term rather than a formal scientific category. That said, it is commonly used informally to describe scores in the Very Superior range (130 and above, roughly the top 2% of the population), and some high-IQ societies set even higher entrance thresholds. "Genius" as commonly used in everyday language also often implies exceptional creative or practical achievement in a specific field, which a general reasoning test score does not directly measure on its own; a very high test score reflects strong performance on the reasoning tasks that particular test happens to sample, not a guarantee of real-world genius-level achievement in any specific domain.

How our own scoring model works, step by step

To be fully transparent (see also the scoring explanation on the homepage): our free tests convert your raw score (number of questions answered correctly out of the total) into a position on the standard bell curve. Getting roughly half the questions right maps to the average score of 100. Each meaningful step above or below that shifts your estimated score up or down the scale, capped at a minimum of 55 and a maximum of 145 so the model never produces an implausible extreme from a very short test. This is a documented, transparent ESTIMATION built for a fast, free, browser-only tool, not a professionally normed score derived from a large representative sample the way a published, individually administered test is.

Average IQ by common context (with sources of variation explained)

You may see claims online about "average IQ by country" or "average IQ by profession". Treat these with real caution: by the very definition of how these tests are normed, the average within any single, properly normed population is set at 100. Comparisons ACROSS different populations, countries, age groups, or professions using different tests, translations, and sampling methods are notoriously difficult to make reliably, and many widely shared "average IQ by country" figures circulating online are drawn from small, inconsistent, or poorly sourced studies. We do not publish or endorse any specific country-by-country or profession-by-profession comparison table here for exactly that reason: doing so responsibly would require citing individually verified, methodologically sound studies for every single figure, which is a different (and much larger) undertaking than a single score-explainer page can responsibly provide.