Research & methodology
Methodology in plain language
This page sets out how the test is put together, how your answers become a score, and what that score can and cannot tell you.
From answers to a score
The test is 25 questions and takes about 12 minutes. When you submit, the scoring happens on our servers rather than in your browser, so the result cannot be edited, refreshed, or nudged into something friendlier.
Your raw performance is then placed on the 100-point scale, where 100 marks the centre and every 15 points is one standard deviation away from it. That placement is what produces a percentile: a comparison against the population rather than a count of correct answers.
The specification
- Questions
- 25
- Typical time
- ~12 min
- Scale mean
- μ = 100
- Standard deviation
- σ = 15
- Scoring
- Server-side
4 traditions we draw from
The questions come out of four established traditions in the measurement of intelligence. All four are public, decades deep, and widely taught, and we use them the way any modern test does, as shared groundwork. We also stand entirely on our own: no researcher and no institution behind these methods has reviewed us, backed us, or put a name to what we built.
Matrix reasoning
Visual grids with one piece missing. Most nonverbal reasoning tests use this format, because it tests logic without leaning on language.
The Wechsler structure
Sorting items into separate reasoning indices. The WAIS reports verbal, perceptual, and working-memory ability apart from each other instead of collapsing everything into one figure.
Stanford-Binet scaling
Deviation scoring, the method that turned a mean of 100 and a standard deviation of 15 into the convention every IQ scale now follows.
Cattell-Horn-Carroll theory
The current map of cognitive abilities, and the reason a well-built test covers the domains it does.
5 cognitive domains, measured in every test
What this score is not
Your result is a careful estimate of how you reason. It is not a clinical diagnosis. A full evaluation by a licensed psychologist is a different exercise with different authority, and we will not dress our number up as one.
We do not run a laboratory, sit inside a university, or publish peer-reviewed papers, and we will not imply otherwise. What we do is build a sharp, honest assessment and put its limits on the page instead of burying them.
The Official IQ Test is a tradename of The Sales Factory B.V., a Dutch company based in Heemstede, Netherlands.
See where your reasoning lands
25 questions, about 12 minutes, and a full cognitive profile waiting at the end of them.