Our mission
IQ Test US exists to give anyone curious about their cognitive profile a free, fast, and scientifically grounded way to estimate their IQ — without paywalls, sign-ups, email collection, or third-party tracking. We believe that basic self-assessment tools should be accessible to everyone, not gated behind subscription services or clinical referrals.
We are not a substitute for clinical psychological testing. We are a starting point: a 10-minute snapshot of how you compare to a normative sample on four core cognitive domains.
What we built
Our test consists of 33 items drawn from the public-domain International Cognitive Ability Resource (ICAR) — an open psychometric framework developed by researchers at Northwestern University and the University of Cambridge for use in academic studies and large-scale online research.
The four domains we measure are:
- Abstract reasoning — pattern recognition in visual sequences (6 items)
- Verbal reasoning — semantic analogies and language logic (4 items)
- Numerical reasoning — number sequences and quantitative logic (3 items)
- Spatial reasoning — matrix reasoning, the gold standard of fluid intelligence (20 items)
Scores are calculated using a normative reference sample, converted to a T-score, and then mapped to the standard IQ scale (mean 100, SD 15), with values clamped to a defensible 55–155 range.
How we differ from clinical tests
Clinical IQ tests like the WAIS-IV or Stanford-Binet are administered one-on-one by a licensed psychologist over 60–90 minutes, include subtests we can't replicate online (working memory under timed conditions, processing speed with motor components), and produce a legally defensible result usable for educational placement, disability evaluation, or research.
What we offer is a self-administered, untimed online estimate. Our score correlates with full-scale IQ but should never be treated as equivalent to a clinical assessment. If you need an IQ score for school placement, gifted programs, disability determination, or legal purposes, see a licensed psychologist.
Known limitations
Honesty about limitations is part of why we trust our score:
- Self-administration — we can't control your environment, focus, or whether you've encountered similar items before. Practice effects and distraction both bias results.
- Limited domain coverage — we measure fluid reasoning well; we don't measure working memory, processing speed, or crystallized verbal knowledge as comprehensively as a clinical battery.
- Online sample bias — our normative reference includes online test-takers who skew younger, more educated, and more digitally literate than the general population. Adjustment is partial.
- 33 items — fewer than a clinical battery (which has 10–15 subtests with multiple items each), so the standard error of our IQ estimate is larger.
For research-grade detail on these issues, see Wikipedia: IQ reliability and validity.
Privacy summary
We collect no personal data. The test runs entirely in your browser. We don't ask for your email, name, age, or location. Your answers, score, and per-domain breakdown are computed client-side and never sent to our servers. You can read our full Privacy Policy for details.
Questions, feedback, corrections
If you spot an error in our content, want to suggest a correction, have feedback on the test interface, or want to discuss our methodology — see our contact page.