Learn About Intelligence with FREE Online Intelligence [IQ] Tests

IQ tests measure the general intelligence skills you possess rather than specific abilities relevant to a particular job. While it's difficult to get a consensus about what "intelligence" actually is, if there's one thing that everyone seems to agree on it's that exercising the brain is as important as exercising the body. These free online IQ tests will help you to do just that, as you gain insight to your cognitive abilities and what that means. 

In this Section you will find...

Part 1: An Introduction to Intelligence and IQ Testing

Discover what intelligence is, how it works, what intelligence tests measure and how they are scored. This background knowledge will help you to make more sense of your IQ (Intelligence Quotient) scores.

Part 2: The Free Online IQ Tests

This section includes a list with links to some of the better free online IQ tests.

Please note, if you are a job seeker or candidate psychometric or aptitude tests rather than IQ tests, are used by many employers and recruiters. These tests focus on specific abilities required for a certain career or job rather than overall general intelligence (which is what this section is about). If this is what you are looking for then then check out our Free Online Psychometric Tests

Online psychometric practice tests

Are you an active job seeker or candidate who is unfamiliar with the psychometric testing process? Do you need to improve your test taking speed, skills and confidence?  

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Prepare for your testing with valid practice psychometric aptitude tests. Get all the tools you need for an optimal learning experience and watch as your scores improve after practising with real test simulations

PART 1: What is Intelligence?

Human intelligence is one of the most fiercely debated subjects within the field of psychology. There are researchers who suggest that intelligence is a single, general ability while others believe that intelligence encompasses a broader range of aptitudes, skills and talents. To avoid confusion (and that debate) this section focuses on a "general intelligence factor" that's measured and expressed as IQ.

There are almost as many definitions of IQ as there are psychologists however in 1994 a group of 52 experts in the study of intelligence and related fields endorsed the following definition of intelligence: 

Intelligence is a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather it reflects a broader and deeper capability for comprehending our surroundings—“catching on,” “making sense” of things, or “figuring out” what to do. (Gottfredson, 1997)


Measuring Your Intelligence Quotient (IQ)

IQ and the G Factor

IQ stands for "Intelligence Quotient". It is the single number derived from a set of standardised tests that measure a person’s ability to comprehend and solve problems in relation to their age group within the general population. These tests of mental ability reflect a single factor, usually abbreviated as "g" (by psychologists). This "g factor" corresponds closely to what the rest of us call intelligence. 

IQ Tests

The first IQ test was developed by two French scientist, Alfred Binet and Theodore Simon, originally for the purposes of assessing children at school so that mentally-handicapped children or children with behavioural problems could receive adequate and appropriate education. This initial test measured skills such as comprehension, judgement, problem-solving and reasoning – and is the basis of the standard modern intelligence test. The original test was modified for adults at Stanford University in the United States, with the new version being named the Stanford-Binet test and the score it produces is called the now famous “intelligence quotient” or IQ. 

What do IQ Tests Measure?

Individuals differ in their ’g factor’ and IQ tests measure those differences in ability by examining two areas of intelligence:

  1. Fluid Intelligence 
    Understanding relationships between various concepts, independent of any previous knowledge or skills, to solve abstract problems. (This decreases with age).

  2. Crystallised Ability 
    Drawing on existing skills, knowledge and experiences to solve problems by accessing information from long-term memory. (This increases with age).

Fluid and Crystallised Intelligence

IQ tests measure fluid and crystallised intelligence by through a range of questions that assess different categories of intellectual ability. For example:

  • Spatial Ability 
    Visualising the manipulation of shapes

  • Mathematical Ability
    Solving problems and using logic

  • Language Ability 
    Completing sentences or recognising words when letters have been rearranged or removed.

  • Memory Ability 
    Recalling things presented either visually or aurally

Scores for the different categories are combined and put through a process called factor analysis. This produces a final score that represents your IQ. It's the reduction of these different dimensions into a single general intelligence score that provokes debate within the field of psychology.


Understanding the IQ Scale and Your Score

Intelligence test scores typically follow a normal distribution on a bell-shaped curve in which the majority of scores lie near or around the average score. On most IQ tests, a score between 90 and 110, (or the median 100 plus or minus 10) indicates average intelligence. As you look further toward the extreme ends of the curve scores tend to become less common. 

(This is the Weschler Adult Intelligence Scale which is slightly different to the one below)

There are many standard IQ tests though and each have their own scoring system

This infographic is an example of an incomplete scale based on some broad generalisations. The fact is if you score 95 you're also within the average IQ range - on most of the standard scales.The point is claiming an IQ of 97 or even 147 is meaningless unless you know the actual type of test that was used.

The scale below is an example of the IQ classification scale produced by Lewis Terman who was the developer of the Stanford–Binet Intelligence scales.

Over 140: Genius or near genius

120 - 140: Very superior intelligence

110 - 119: Superior intelligence

90 - 109: Normal or average intelligence

80 - 89: Dullness Normal

70 - 79: Mild

50 - 69: Moderate

20 - 49: Severe

Below 20: Profound

IQ and Intelligence on the Job

General intelligence is a key to determining many life outcomes such as academic success, job performance and advancement.

The importance of our general intelligence in job performance is related to complexity. Occupations differ considerably in the complexity of their demands, and as that complexity rises, higher levels of general intelligence become a bigger asset and lower levels a bigger handicap. The classification scales below reflect this and indicate how scores can be used to establish cut off points for entry into different types of jobs and educational programmes. 

Best Estimate of IQ Differences for Adults in Different Occupations
(Wechsler Adult Intelligence Scale)

WAIS-R Mean IQ RangeOccupational Category

110 -112Professional and technical
103 -104Managers, clerical, sales
100 -102Skilled workers
92-94Semi Skilled workers
87-89Unskilled workers

Kaufman, Alan S. Assessing Adolescent and Adult Intelligence. Allyn and Bacon, 1990

Measured Intelligence and Education
(Wechsler Adult Intelligence Scale)

WAIS-R Mean IQOccupational Category

125Mean of persons receiving Ph.D. and M.D. degrees
115Mean of college/university graduates
105Mean of high school graduates
100Average for total population
75About 50-50 chance of reaching ninth grade

Matarazzo, Joseph D. Wechsler's Measure and Appraisal of Adult Intelligence, 5th Edition. Oxford University Press, 1972.


Smart Doesn't Guarantee Success

The value of IQ tests is that they measure general cognitive ability which has been proven to be a fairly accurate indicator of someone's intellectual potential. Being brighter also helps as the daily activities of everyday life require reasoning and decision making — an exercise of general intelligence. However, a person’s intelligence level doesn't guarantee either success or failure in life as many other personal traits and circumstances come into play. Daniel Goleman, a noted psychologist at Harvard University, puts it this way: 

"I would say that IQ is the strongest predictor of which field you can get into and hold a job in, whether you can be an accountant, lawyer or nurse, for example. But once you are in that field, emotional intelligence emerges as a much stronger predictor of who will be most successful, because it is how we handle ourselves in our relationships that determines how well we do once we are in a given job."

The bottom line is that your IQ score will give you a pretty accurate indication of your ability to think, reason and solve problems which will have a bearing on many aspects of your life. However, IQ is not the be all end all of a person's abilities. IQ scores don't measure a myriad of other abilities that can lead to many different successes in life.

Brainiacs - What is a Genius?

The world is full of smart people who do amazing things but experts disagree on exactly what makes a person a genius. Some specify a particular IQ score, such as 140 or higher, while those who disagree with the 140-point cutoff argue that people often display intelligence that can't be measured on a standardised IQ test. Dr. Abbie Salny, who was the American Mensa's supervisory psychologist for 23 years, had this to say in an excerpt from the Mensa Bulletin: 

It has been said that a 140 IQ is a "genius" score, however there is no definition, as such, in either of my psychological dictionaries about "genius." Neither is there an IQ score ranked as "genius." Furthermore, a true genius may not score particularly well on a standard group IQ test. We know a Nobel Prize winner who never scored at Mensa level on a school IQ test - he was too busy seeing all the alternate possibilities for each answer. At the present time, all IQ scores are read off of tables. Now there are almost no tests in use that will give extraordinary high IQ's except those with very large standard deviations. And really, those who are what we may call a genius don't need a score to prove it.

Another respected psychologist Arthur Jensen reinforces this position but from a slightly different perspective. He states that IQ differences in the upper part of the scale have far less personal implications and are generally of lesser importance for success than certain traits of personality and character.

The World Genius Directory: Although there's no "official" genius score there are organisations, like Mensa, for the few who possess "extreme talent". The Genius Directory includes an up to date Who's Who of some of the highest IQ test scorers in the world. 

Venus and Mars - Gender and Intelligence

While men and women may think differently, there's no evidence that either gender is innately more intelligent than the other.

What researchers have discovered is that when it comes to intelligence, people have two types of brains: One type has a significant amount of gray tissue (information processing centres), and a second type has a significant amount of white tissue (tissue that networks the information processing centres). The study found that female brains have about 10 times more white matter than male brains, and male brains have about 6.5 times more gray matter. What does this mean? While men and women have different types of tissue in their brains, overall performance is equal - we just excel at different types of tasks.

Older but Wiser - Intelligence and Age

"The error of youth is to believe that intelligence is a substitute for experience, while the error of age is to believe experience is a substitute for intelligence”

Lifespan changes in crystallised and fluid intelligence

Until the age of about 25, most of us improve our problem-solving skills and memory. We peak at about age 28, and then comes the slide, with each passing decade performance on standardised reasoning tests declines (our fluid intelligence). However, the good news is that the long-term memory of older adults appears to store and use information better than short-term memory (our crystallised intelligence) so, while older people may lack the cognitive skills of their youth, they have something that can't be measured on any standardised test - wisdom.

Wisdom, expertise and practical knowledge based on years of experience are valuable assets. Younger people may perform with greater speed and more agility, but the older generation can see the big picture, relationships and trends based on experience.

It's definitely easier to produce an IQ score that's lower than your true IQ

When it comes to testing, keep in mind that there are outside factors that may have a negative impact on your score - taking test on a bad day, being excessively nervous or spending too much time on a few difficult items can artificially lower your score. Understanding how an IQ test works, practice, familiarising yourself with the type of problems and being well rested will help you to achieve a truer score. 

Can you increase your IQ?

IQ tests measure your ability to understand ideas and not the quantity of your knowledge so learning new information does not automatically increase your IQ. There is evidence that maintaining an intellectually stimulating environment (by learning new skills) and some forms of specialised brain training boosts some ability but these changes aren't permanent. Scientists are working on it but they have yet to discover reliable and ethical ways to manipulate a permanent rise in IQ - which is why the now famous Flynn Effect is also known as the IQ paradox.

University of California, Irvine. "Intelligence In Men And Women Is A Gray And White Matter." ScienceDaily. Jan. 22, 2005. (Nov 19, 2010) Spearman, C. (1904). "General intelligence," objectively determined and measured. American Journal of Psychology 15, 201-293 Gottfredson, L. S. 1986 The g Factor in employment. Special issue of the Journal of Vocational Behavior, 29, 293-450. Herrnstein, R. J. & Murray, C. 1994 The Bell Curve: Intelligence and Class Structure in American Life. New York: The Free Press Jensen, A. 1980 p 113. Bias in Mental Testing. New York: Free Press

The IQ Paradox

The IQ paradox is simply to do with the large gains over time in intelligence test scores. In his study of IQ tests scores for different populations over the past sixty years, Professor James Flynn discovered that IQ scores increased from one generation to the next for all of the countries for which data existed. This interesting phenomena has been called "the Flynn Effect."  In this short (3 min) video Professor Flynn describes the global increase in IQ scores as well as some of the possible reasons.

James R. Flynn is an emeritus professor of politics at the University of Otago in New Zealand  and author of "What Is Intelligence?: Beyond the Flynn Effect" and "Are We Getting Smarter? Rising IQ and the Twenty-First Century."

A Summary of the Flynn Effect

Our ancestors were grounded in the concrete world. They used classifications based on functional relationships (this eats that) or similarities in appearance (this looks like that). However over time, and in response to an increasingly complex world, people have developed new "habits of mind". These are more conceptual and have boosted IQ scores in specific categories - for example "similarities" has seen enormous gains (24 points between 1947 and 2002 in the Weschsler Intelligence Scale for Children). It would appear that people are not growing ‘smarter’ but they are growing better at very specific cognitive skills.

And IQ scores continue to climb as Flynn recently reported, “To my amazement, in the 21st century the increases are continuing. The latest data show the gains in America humming right along at the old rate of three tenths of a point a year.”

The Flynn Effect suggests that intelligence is more malleable and subject to environmental effects than originally thought. That said, researchers have yet to answer many of the questions about why this effect occurs and until they do, the Flynn effect will remain a paradox. 

PART 2: The Free Online IQ Tests

The majority of free online IQ tests are at best a simplification. They test a narrow range of thinking skills and wont give you a true indication of your IQ so don't take the results too seriously. Your actual IQ score can vary plus or minus five points since it is very difficult to get an IQ score with complete accuracy. The best results are obtained from reliable validated IQ tests and when more than one test is administered.

Disclaimer: This information has been compiled by Excellerate to assist you with your career development. All links are provided in good faith. Those that are listed were found to contain useful practice tests, questionnaires or other material at the time of their inclusion. The fact that a link to a website, or other resource, is included, does not constitute a professional recommendation or endorsement of the services, nor is warranty given as to the completeness or accuracy of the information provided by the sites listed. Each link will take to you the site where you should use your discretion when providing personal details or acting upon the information provided.

Professional IQ Tests International High IQ Society | Free Online IQ Test

A multiple choice timed test consisting of 50 questions assessing your verbal, math and spatial reasoning and problem solving skills. The High IQ Society website states that they're the first to provide a range of standardised free IQ tests on the internet. And with more than 20 million users since 2001 their question pool enables them to provide more than 2.4 billion tests. 

IQ TestIQ Test - the original online test 

In addition to measuring your general IQ, this test assesses your performance in 13 different areas of intelligence, revealing your key cognitive strengths and weaknesses.

Fun Mensa Test | Free Online IQ Test 

From Mensa International this quiz is provided for entertainment purposes only; it is not an IQ test. Answers to questions and discussion of the answers are provided at the time you submit your answers. Mensa accepts anyone with an IQ score in the top two per cent of the population, measured on a recognised IQ test (Note there are several websites claiming to offer online 'Mensa IQ tests' however British Mensa does not currently operate an online IQ test and is unable to accept online test results as evidence for membership to the society) 

Spatial Intelligence Test | Free Online IQ Test 

This questionnaire includes 208 questions and provides you with a detailed feedback report. It measures your spatial intelligence - your ability to look at and understand the spatial world. The higher your spatial IQ, the more easily you will be able to learn and to solve problems that involve looking at and understanding what you see. 

FunEducation | Free Online IQ Test 

This free online IQ test with only 43 Questions measures several key areas including word analysis and spatial reasoning. Your raw IQ score is scaled to provide your IQ relative to the normal distribution of intelligence scores. 

Test The Nation | BBC Free IQ Quiz 

This not a recognised IQ test however, achievement of a score of 120 or more in this IQ quiz would suggest you might like to have a go at a full Mensa IQ test. You can also compare your results with the rest of the UK.

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Free Online Personality Tests

Free Online Personality Tests

There are several personality traits which are positively related to general intelligence. These traits influence how you use your cognitive abilities. Discover what these traits are and take a free online personality test to learn about your type
Free online Psychometric tests

Free Online Psychometric Tests 

Many employers and recruitment agencies use a form of psychometric testing as part of their selection process. For some people this can be quite daunting. Practise tests can help you to prepare - not only will know what to expect but you can identify areas to brush up on

Free online intelligence IQ tests

Free Online IQ Intelligence Tests

The psychometric tests that are used to select people for jobs are not IQ tests but are designed to see how you apply your intelligence. IQ is an index of general intelligence. Learn more about IQ and try some free online IQ tests in this section.

Free online multiple intelligence tests

Free Online Multiple Intelligence Tests

There is considerable debate about the use of the single "g factor" to define intelligence. Learn about two influential theories of Multiple Intelligence and discover your unique combination by taking a free online multiple intelligence quiz
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