How long does a real IQ test take?

A clinically administered adult IQ test such as the WAIS-IV takes 60 to 90 minutes to complete, plus 30 to 60 minutes of scoring and report-writing by the clinician. Brief screening instruments such as the WASI-II take about 30 minutes. Online screening tests vary from 5 minutes (very brief, very imprecise) to 45 minutes (more thorough, still less precise than clinical tests). The 25-item screener on this site takes about 12 minutes for most test-takers. Length matters because IQ measurement precision improves with item count: a 10-item test cannot have the same standard error of measurement as a 60-item test, regardless of how good the items are.

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.