WAIS-IV Explained: The Subtests, the Scores and Its Successor

The Test in Brief

David Wechsler released his first adult scale, the Wechsler-Bellevue, in 1939, arguing that the Binet items of the day were built for children and were not valid for adults. The WAIS-IV is the fourth full revision of the adult line. Pearson published it in 2008 and normed it on 2,200 people in the United States aged 16 to 90, matched to Census Bureau demographics. A Canadian extension of the standardization added 688 people across the same ages.

An examiner gives the test one-to-one, on paper or digitally. It is used in clinical, neuropsychological, educational and forensic evaluations: anywhere a court, a clinic or a school needs a defensible estimate of adult cognitive ability. It is not a screening quiz, and nothing on the web reproduces it. For background on how test makers turn raw answers into an IQ, see how IQ tests work.

The 15 Subtests, Index by Index

The WAIS-IV has ten core subtests and five supplemental ones. The core ten produce the Full Scale IQ. A supplemental subtest can stand in when a core subtest is spoiled, for instance by an interruption or a physical limitation. The format notes below describe task types only; actual items are confidential.

Digit Span itself has three parts: forward, backward and sequencing. The four indexes replaced the Verbal IQ and Performance IQ of earlier editions, which the WAIS-IV dropped.

How the WAIS-IV Scores

Raw points on each subtest convert to scaled scores, mean 10 and standard deviation 3, using norms for the examinee's age band. Sums of scaled scores then convert to index scores and the Full Scale IQ, all on the familiar metric of mean 100 and standard deviation 15. The FSIQ runs from 40 to 160. Each composite comes with a percentile rank and a confidence interval, because a single administration carries measurement error of a few points.

The WAIS-IV also offers the General Ability Index (GAI), built from six subtests: Similarities, Vocabulary and Information, plus Block Design, Matrix Reasoning and Visual Puzzles. It leaves out working memory and processing speed. Examiners use it when slow processing or weak short-term memory would otherwise mask reasoning ability.

For the same ranges under other tests' labels, see the IQ classification chart; to turn any score into a percentile, use the IQ percentile calculator.

The 160 Ceiling

The WAIS-IV cannot report a Full Scale IQ above 160. That is four standard deviations above the mean, a level reached by roughly 1 adult in 31,600 on a normal curve, and the norm sample of 2,200 contains too few people at that level to rank them precisely. An adult who answers nearly everything correctly simply reaches the top of the scale. Claims of a measured adult IQ of 180 or 200 on a Wechsler test are therefore claims the test cannot support. Our page on an IQ of 160 explains the statistics, and the top 1 percent covers the more common high range.

The WAIS-5: What Replaced the WAIS-IV

Pearson published the WAIS-5 in 2024 for the same ages, 16:0 to 90:11, with new norms collected in 2023 and 2024 and co-normed with the Wechsler Memory Scale, Fifth Edition. Four changes matter most:

• Five primary indexes instead of four. Perceptual Reasoning is split into Visual Spatial and Fluid Reasoning, matching the children's WISC-V.
• A shorter Full Scale IQ. Seven subtests instead of ten: Similarities, Vocabulary, Block Design, Matrix Reasoning, Figure Weights, Digit Sequencing and Coding. Pearson puts it at about 45 minutes.
• New and retired subtests. Running Digits, Set Relations, Naming Speed Quantity, Spatial Addition and Symbol Span are new. Picture Completion and Cancellation are gone. Information and Arithmetic, core subtests in the WAIS-IV, are now secondary, alongside Comprehension and Letter-Number Sequencing.
• Later start points for suspected giftedness, which shorten testing for very able adults.

The WAIS-IV did not vanish overnight. Pearson still lists its manuals and forms and states that most practitioners move to a new edition within 8 to 12 months of release. It also reminds users that professional testing standards make them responsible for justifying an older edition when a newer one exists. A WAIS-IV score from 2015 is still a valid score from 2015. A new evaluation today will more likely use the WAIS-5.

Retesting and Practice Effects

Adults score higher the second time. In the WAIS-IV retest study reported in the technical manual, examinees were retested after 8 to 82 days, 22 on average. Mean scores rose on every subtest. The gains were smaller on Verbal Comprehension and Working Memory and larger on Perceptual Reasoning and Processing Speed, where novelty is part of the challenge.

Christopher Ray, writing in 2009 on practice effects in capital cases, pointed to the WAIS-IV manual's own admission that the shortest retest interval free of significant practice effects had not been determined, and advised against readministering most intelligence tests within a year. When a retest within six months is unavoidable, Ray urged examiners to strongly consider a different IQ test. The lesson for anyone comparing two scores: a five-point rise after a few weeks may be practice, not change.

Who Gives It and What It Costs

Pearson sells the WAIS-IV at qualification level C, the tier that permits purchase of all its assessments and is held mainly by licensed psychologists. Testing happens in clinics, hospitals, private practices, universities and forensic settings. Fees for an evaluation are set by the examiner and are not published by Pearson.

Pearson does list materials prices. In October 2026 the WAIS-IV Administration and Scoring Manual and the Technical and Interpretive Manual each listed at $344, a pack of 25 record forms at $202.10 and a digital score report at $3. The WAIS-5 complete print kit listed at $1,784. None of that buys an online version for the public. The free geniuses.club IQ test is a practice screener, and our guide to online IQ test accuracy explains what such screeners can and cannot tell you. More explainers sit in our IQ guides, including the children's version, the WISC-V.

Editorial standard: IQ figures for historical figures are retrospective estimates and are labeled as such; scores for living people appear only when the person disclosed them or a reputable outlet reported them. Corrections: contact the editors.