In short: the Wechsler Adult Intelligence Scale (WAIS) is the most widely used professional IQ test for adults. The current edition, the WAIS-5, was published in 2024 for ages 16 to 90. A psychologist gives it one to one: seven subtests produce your full scale IQ in about 45 minutes, and ten subtests produce five more detailed index scores in about an hour.
What is the WAIS?
The WAIS is a set of short tasks, called subtests, that together measure how well an adult reasons, remembers and processes information. It is published by Pearson and used by clinical, educational and neuropsychologists around the world, for example to assess learning difficulties, to track changes after a brain injury, or to support applications for extra time in exams.
WAIS-5 figures from Pearson.
From 1939 to the WAIS-5
The test is named after David Wechsler, chief psychologist at Bellevue Hospital in New York. Earlier tests were designed for children and scored by "mental age", which worked badly for adults. Wechsler's test compared adults with others of the same age and added tasks that didn't depend on language, such as arranging blocks. Each edition since has been re-normed on a new sample of people, so scores stay comparable with the population of the day.
- Wechsler-Bellevue Intelligence ScaleThe first version, with verbal and non-verbal "performance" tasks.
- WAISThe first Wechsler Adult Intelligence Scale.
- WAIS-RA revision with six verbal and five performance subtests.
- WAIS-IIIAdded four index scores alongside the verbal and performance IQs.
- WAIS-IVDropped the verbal and performance IQs in favour of four index scores.
- WAIS-5Current edition, normed in 2023 and 2024, with five index scores.
WAIS, WISC and WPPSI: which test for which age?
The WAIS has two sister tests for children. They share the same design and scoring, so results can be followed from childhood into adult life. Where the age ranges overlap, the psychologist chooses whichever test fits the person best.
- WPPSI-IV (Wechsler Preschool and Primary Scale of Intelligence): ages 2 years 6 months to 7 years 7 months.
- WISC-V (Wechsler Intelligence Scale for Children): ages 6 to 16 years 11 months.
- WAIS-5 (Wechsler Adult Intelligence Scale): ages 16 to 90 years 11 months.
What happens during the test
The WAIS is given one to one in a quiet room. The examiner reads standard instructions, shows pictures or puzzles in a stimulus book or on a tablet, and records your answers. Some tasks are spoken, some involve pointing to an answer, and a few, like arranging blocks, are hands-on.
- Each subtest starts easy and gets harder. Most begin at a set starting point, with a later start for very able people, and stop after a set number of wrong answers, so nobody sits through dozens of questions that are far too hard.
- Some tasks are timed. Speed matters on the processing speed tasks and on some puzzles, but most verbal questions have no time limit.
- Nobody gets everything right. The test is built to find the limit of your ability, so running into questions you can't answer is expected.
- The examiner watches how you work, not just your answers: concentration, frustration or fatigue can all be noted in the report.
The five index scores and ten main subtests
The WAIS-5 groups its ten main subtests into five index scores, each covering one broad ability. Seven of the ten also go into the full scale IQ, the single overall score. Choose an index to see its subtests.
Verbal Comprehension Index
How well you understand and use words, and the knowledge you have built up.
Visual Spatial Index
How well you analyse shapes and picture how parts fit together.
Fluid Reasoning Index
How well you find rules and solve problems you haven't seen before.
Working Memory Index
How well you hold information in mind and work with it.
Processing Speed Index
How quickly and accurately you work through simple visual tasks.
Descriptions are our own summaries of each task, not real test items. Subtest structure from Pearson and the British Psychological Society.
Beyond these ten, the WAIS-5 has further optional subtests that a psychologist can add for a closer look at particular abilities, such as a test of general knowledge, and extra index scores built from them.
Our guides look at four of these abilities in depth: verbal reasoning and verbal IQ, spatial reasoning, abstract reasoning (the core of fluid reasoning) and processing speed, including what a low or high index score means.
How the WAIS is scored
Your answers go through several steps before they become an IQ score. At each step, you are compared with people of your own age from the test's national sample.
Subtest scaled scores have an average of 10 and a standard deviation of 3, so most people score between 7 and 13 on any one task. The index scores and full scale IQ use the familiar IQ scale with an average of 100 and a standard deviation of 15. Use the slider to see how the two scales line up.
A professional report doesn't treat any score as exact. Each index and the full scale IQ come with a confidence interval, typically a range of several points either side, and the psychologist looks at the pattern across indexes as well as the overall number. Our article on how accurate IQ tests are explains why that range matters, and the IQ scale and score ranges guide shows what each level of full scale IQ means.
What's new in the WAIS-5
- Five index scores instead of four. The WAIS-IV combined visual-spatial and fluid reasoning into one "perceptual reasoning" index. The WAIS-5 reports them separately.
- A shorter full scale IQ. It now comes from seven subtests and takes about 45 minutes.
- New tasks. Running Digits (working memory), Set Relations (fluid reasoning) and Naming Speed Quantity (processing speed) are brand new, and Symbol Span and Spatial Addition, previously part of the Wechsler Memory Scale, join the WAIS for the first time.
- New norms. The comparison sample was tested in 2023 and 2024, so your score is compared with today's adults.
- Paper or digital. It can be given with printed materials or on two tablets, one for the examiner and one for the person being tested.
Who can give the WAIS, and how to get tested
Pearson only sells the WAIS to professionals at its highest qualification level, usually psychologists with specialist training in assessment. That is deliberate: the questions are kept confidential so that nobody can rehearse them, and interpreting the results takes clinical judgement.
If you want a WAIS assessment:
- Start with your reason. For school or university support, ask the institution which assessments it accepts. For health concerns, such as memory problems or a brain injury, start with a doctor, who can refer you.
- Find a qualified psychologist, such as a clinical, educational or neuropsychologist, and ask whether they use the WAIS-5 and what the assessment includes.
- Ask what you will receive. A good assessment ends with a written report explaining your scores, not just a number.
- Mention any recent testing. Practice inflates results: a 2018 review of retesting studies found higher scores on second and third attempts before the gains levelled off. The psychologist needs to know so they can read your result fairly.
WAIS vs online IQ tests
There is no single official IQ test. When people ask for one, they usually mean a professional test such as the WAIS-5: given one to one by a qualified psychologist and scored against national norms. Here is how it compares with a good online test.
| WAIS-5 | A good online test | |
|---|---|---|
| Who gives it | A qualified psychologist, one to one | You, on your own device |
| Time | 45–60 minutes for the core tasks | Usually 20–40 minutes |
| What it covers | Verbal, visual-spatial, fluid reasoning, working memory and speed | Usually reasoning puzzles; some cover several areas |
| Result | An official score with a written report | An estimate for personal insight |
| Cost | A professional fee | Often free |
An online test can't replace a WAIS, but it is a reasonable first step if you are simply curious. Our free IQ test covers fluid, logical, spatial and numerical reasoning in 36 questions, and our guide What is IQ? explains what these abilities are and what a score can tell you.
Frequently asked questions
How long does the WAIS take?
The seven subtests needed for a full scale IQ take about 45 minutes, and the ten main subtests that give all five index scores take about 60 minutes, according to Pearson. A full assessment, with an interview and other tests, often takes longer.
Can I take the WAIS online by myself?
No. The WAIS is only sold to qualified professionals and is always given by a trained examiner. The digital version runs on two tablets, one for the examiner and one for you, but the examiner still leads the session.
What is a good score on the WAIS?
The full scale IQ uses the standard IQ scale, where 100 is average and about half of people score between 90 and 109. Scores of 110 and up are above average, 120 puts you ahead of roughly 91% of people, and only about 2 in 100 reach 130.
What is the difference between the WAIS and the WISC?
They are sister tests from the same family. The WISC is for children aged 6 to 16, and the WAIS is for people aged 16 to 90. A third test, the WPPSI, covers children from 2 and a half to 7.
Can you study for the WAIS?
Not in any useful way. The questions are kept confidential, and seeing them in advance would make the result meaningless. The best preparation is ordinary: sleep well, eat beforehand, bring your glasses if you need them, and tell the examiner if you have taken a similar test recently.
Is the WAIS the same as the Stanford-Binet?
No. They are different tests from different publishers, built in different ways. Both report scores on the same scale, with an average of 100 and a standard deviation of 15, so their results can be read in the same way.
Sources
- Wechsler Adult Intelligence Scale, Fifth Edition, Pearson: ages, qualification level, administration time and formats.
- WAIS-5 overview brochure, Pearson: index scores and primary subtests.
- What's new with the WAIS-5?, Pearson: new subtests and 2023–2024 norms.
- The WAIS V: changes to test structure and content, British Psychological Society: the seven full scale IQ subtests.
- Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition, Pearson: WPPSI-IV age range.
- Wechsler Adult Intelligence Scale, Wikipedia: history of the editions.
- Scharfen, J., Peters, J. M. and Holling, H. (2018). Retest effects in cognitive ability tests: a meta-analysis. Intelligence, 67, 44–66.
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