How Long Does an IQ Test Take? Every Test, Compared

The honest answer is "anywhere from 10 minutes to half a day". The test itself is usually the short part. What makes a professional assessment long is everything around it: the interview, the breaks, the scoring and the report.

Below are the published times for every major IQ test, then what to expect from a psychologist, from Mensa and from online tests.

How long does each IQ test take?

Test	Who gives it	Testing time
Typical online IQ test	You, at home	10 to 40 minutes
LifeScore IQ test	You, at home	About 12 minutes (25 questions)
Wonderlic	Employers	12 minutes (50 questions)
KBIT-2 (brief test)	Psychologist	About 20 minutes
WASI-II (short form)	Psychologist	15 minutes (2 subtests) or 30 minutes (4)
Wide Range Intelligence Test (WRIT)	Psychologist	About 30 minutes
Raven's Standard Progressive Matrices	Psychologist or group	20 to 45 minutes, usually untimed
Raven's Advanced Progressive Matrices	Psychologist or group	40 to 60 minutes
WAIS-5 (adults, current edition)	Psychologist	About 45 minutes for the full-scale IQ, about 60 for all primary subtests
WAIS-IV (adults, previous edition)	Psychologist	60 to 90 minutes for the core subtests
WISC-V (children 6 to 16)	Psychologist	45 to 65 minutes
Stanford-Binet 5	Psychologist	15 to 75 minutes, depending on the form
British Mensa home test	You, at home	45 minutes
British Mensa online supervised test	Remote proctor	About 1.5 hours (under an hour of questions)
British Mensa in-person test	Test centre	About 2.25 hours
American Mensa admission test	Proctor	1 to 2 hours

Times come from the publishers and from Mensa where they publish them. The table shows testing time only, not the whole appointment.

How long does a WAIS test take?

The Wechsler Adult Intelligence Scale is the test most psychologists use for adults. Its timing depends on the edition.

• WAIS-5, released in 2024, takes about 45 minutes for the seven subtests that make up the full-scale IQ, and about 60 minutes for the ten primary subtests. Pearson, the publisher, says that is about 20 minutes faster than the WAIS-IV.
• WAIS-IV takes about 60 to 90 minutes for the core subtests, and longer if the psychologist adds optional ones.

Real sessions often run longer than the manual says. In a study of the children's version (WISC-IV), the ten core subtests took an average of 72 minutes, ranged from 42 to 100 minutes, and ran past 80 minutes for almost a third of the children (Ryan and colleagues, 2007). People who think carefully, who get tired or who need breaks take longer, and that is fine: most of the subtests are not a race.

How long does a psychologist's IQ assessment take, start to finish?

The test is one part of a longer process. A typical private assessment looks like this:

Step	Typical time
Phone consultation or intake form	20 minutes to an hour
Intake interview on the day	15 to 30 minutes
Testing	1 to 2 hours, with breaks
Feedback session	30 to 60 minutes, same day or a week later
Written report	1 to 4 weeks

So plan for two to four hours of appointments and a report a few weeks later. Assessments for a diagnosis, such as ADHD, dyslexia or a brain injury, add more tests and can take a full day or two sessions. Our guide to how much an IQ test costs explains why that time is expensive.

How long is the Mensa test?

Mensa offers several formats, and the timings differ a lot:

• British Mensa in person: about 2¼ hours at a test centre, including instructions and two separate tests.
• British Mensa online: about 1½ hours with a remote proctor, of which under an hour is spent answering questions. You need photo ID, a webcam and a quiet room. Results arrive within about ten days.
• British Mensa home test: 45 minutes on paper, for an indicative score only.
• Mensa's free online workout: up to 15 minutes. It is practice, not an IQ test.
• American Mensa: one to two hours, and you can only sit each test once every eight weeks.

If you want to see the style of questions before you book, try our Mensa practice test.

How long does an online IQ test take?

Most take 10 to 40 minutes. Three things decide the length:

1. The number of questions. More items give a steadier score, up to a point. Very short tests of five or ten items can swing a lot from one attempt to the next.
2. The time limit. A fixed limit keeps the test fair. An untimed online test lets anyone solve hard puzzles slowly, which inflates scores.
3. What it measures. A test of one ability, such as matrix reasoning, can be shorter than a battery that also covers vocabulary, memory and speed.

The LifeScore IQ test uses 25 visual matrix puzzles with a 12-minute limit. That is long enough for a stable reading of reasoning ability and short enough to finish in one sitting. It does not test vocabulary, memory or speed separately, so it is narrower than a clinical battery, and it is an estimate rather than a clinical IQ. For more on how short a test can be and still be useful, see our quick IQ test guide.

Are IQ tests timed?

Mostly, yes, but the time limits do different jobs.

• Speed tests give you too little time to finish. The Wonderlic, with 50 questions in 12 minutes, is mostly a test of working fast. A 20-minute version of Raven's matrices was given to British military recruits from 1942 for the same reason: it had to process many people quickly.
• Power tests give generous time, so the score reflects how hard a problem you can solve rather than how fast you work. Raven's matrices are often given untimed for this reason, and most WAIS subtests allow plenty of time.

Most good tests sit in between: a limit firm enough to stop people spending an hour on one item, but loose enough that careful thinking is not punished. On matrix puzzles in particular, rushing usually costs more points than it saves. Our guide to solving matrix IQ questions shows how to pace them.

Do longer IQ tests give more accurate scores?

Up to a point. Each extra well-made question reduces the random error in your score, which is why clinical tests use dozens of items across several subtests. But the gains shrink as tests get longer, and a long test full of easy or badly made questions is worse than a short, well-built one.

The bigger difference between a 12-minute online test and a 90-minute WAIS is breadth, not just length. The WAIS measures verbal comprehension, working memory and processing speed as well as reasoning, so it gives a fuller picture. A short visual test measures one important part of intelligence well, which is why its result is best read as an estimate of reasoning ability.

How long does it take to get IQ test results?

Test	When you get your result
Online test	As soon as you finish
British Mensa online supervised	Within about 10 days
British Mensa in person	By email once marked
American Mensa	Within days (pass or fail only)
Psychologist	Brief feedback within a week; full written report in 1 to 4 weeks

Common questions

Can you take an IQ test in 10 minutes?

You can take a short one, but very short tests are less steady. Around 20 to 30 well-made items in 10 to 15 minutes is enough for a reasonable estimate of one ability. It is not enough for a full clinical profile.

Does taking longer lower your score?

On most tests, no. Taking your time within the limit tends to help on reasoning puzzles. What lowers scores is running out of time before you reach the questions you could have answered, so keep moving and come back to any item that stalls you.

How long should I spend on each question?

Divide the time limit by the number of questions and treat it as an average, not a rule. On a 25-question, 12-minute test that is just under 30 seconds each. Early questions take less, later ones more.

Should I prepare before the test?

A little. Sleep properly and see the question format once. Heavy practice can inflate a score without changing your ability. See how to prepare for an IQ test.