IQ tests explained

The named IQ tests, explained

Raven's, the WAIS, Stanford-Binet, Cattell and Mensa come up in every conversation about IQ. This guide says what each one is, who can take it, what it costs and how to try questions in its style.

Reviewed September 2026By the LifeScore Editorial TeamEditorial policy

Pick a test

The tests side by side

Named IQ tests compared
TestFormatCan you take it online?Score scale
Raven's Progressive MatricesNon-verbal matrix puzzlesNo, only style-alike practicePercentile or standard score by age
WAIS-5Ten or more subtests, one-to-oneNo, needs an examinerMean 100, SD 15
Stanford-Binet 5Five factors, verbal and nonverbal, one-to-oneNo, needs an examinerMean 100, SD 15 (older editions SD 16)
Cattell Culture FairFour short non-verbal subtestsNo, only style-alike practiceMean 100, SD 24
Mensa admission testSupervised reasoning testUK proctored online test onlyTop 2% qualifies

How online IQ tests fit in

A score means something only when it is compared with a norm group under standardised conditions. Professional tests meet that standard. Most free online tests do not publish a norming sample, and they have no supervision, so their scores are estimates.

That does not make them useless. A well-made online reasoning test can show you how you handle patterns, sequences and rules, and can be a first step before deciding whether to pay for a professional assessment. Just do not treat its number as a Wechsler IQ. To see how test scores you already have relate to IQ, use the score converters.

IQ tests: common questions

What is the most accurate IQ test?+

Individually administered tests given by a psychologist, such as the WAIS-5 and the Stanford-Binet 5, are the most accurate. They use supervised conditions and large, recent norm groups. Free online tests cannot match them.

Which IQ tests can I take at home?+

None of the professional tests can be taken by yourself online. Mensa UK offers a proctored online test, and many websites offer free tests in the style of the professional ones. Those give estimates, not official scores.

What is the difference between Raven's, the WAIS and Cattell?+

Raven's and Cattell are mainly non-verbal reasoning tests. The WAIS is a broad battery with verbal, spatial, reasoning, memory and speed measures. Their scores use different scales, so compare percentiles rather than raw IQ numbers.

Why do IQ tests use different scales?+

Every IQ scale sets the average at 100, but the spread differs. Wechsler tests use a standard deviation of 15, older Stanford-Binet editions 16, and Cattell 24. A score of 130 on the first, 132 on the second and 148 on the third are the same level.

Is the LifeScore test one of these?+

No. LifeScore's test is a 25-question online visual reasoning test. It is not any of the named tests here, it is not clinically normed, and it is not a substitute for a supervised assessment.