What IQ do I need to join Mensa?

Mensa requires a score at or above the 98th percentile on a battery of approved cognitive tests. On the WAIS-IV and Stanford-Binet 5, this corresponds to a full-scale IQ of approximately 130. On the Cattell IIIB (which uses a standard deviation of 24 instead of 15), the equivalent score is approximately 148. Mensa accepts scores from a long list of approved tests but does not accept results from online IQ tests, including this one. To qualify, you must take an in-person Mensa-administered test or submit prior results from a clinically administered test. About 1 in 50 adults qualifies by this standard.

This question comes up frequently from users of free online IQ tests and from people considering whether to pursue a clinical evaluation. The full answer depends on context — what the score will be used for, how recently the test was administered, and what other information is available. The brief answer above captures the broad consensus from the published research literature; the linked deep-dive articles cover the underlying evidence in more detail.

Related considerations include the standard error of measurement on the relevant test, the population the test was normed against, and the specific cognitive abilities the test samples. A score is much more informative when interpreted alongside these contextual variables than when reported as a bare number.

If this answer raises further questions, see the related FAQ entries listed in the sidebar and the longer-form articles on the same topic in the article library. The site is designed to provide layered depth: the FAQ entries offer concise answers, the deep-dive articles offer the underlying research, and the score-interpretation pages tie the abstract concepts to specific result bands.