Is an online IQ test accurate? What the number does and does not tell you
An online IQ test gives you a number, but rarely an IQ. A real IQ test is normed on a large group, taken under supervision, and has a mean of 100 with a standard deviation of 15. A free test on a website usually lacks that norm group, so a score of 128 says something about the site and little about you.
By the Skillido editorial team. Published on .
Type "free IQ test" into a search engine and you can have a number within fifteen minutes. Almost every site near the top will give you one. What they rarely tell you is what that number is worth. This article explains where an IQ score comes from, which parts of that an online test can copy and which parts it cannot, and when you need the real thing. At the end we say what our own test measures. It is not an IQ, and we would rather tell you that now than have you find out after five minutes.
What an IQ score is
An IQ is a position within a group. The scale is built so that the average of the population sits at 100 and the standard deviation is 15 points. About two thirds of people therefore score between 85 and 115, and a score of 130 belongs to roughly two in a hundred. The number tells you how your answers compare with those of a large group of people who did the same tasks under the same conditions. That group is called the norm group, and without a norm group there is no IQ, only a count of right answers.
How a real test is taken
A recognised intelligence test is administered by a psychologist, usually in a single session of an hour or more, with fixed instructions and a fixed time per section. Before it was ever sold, the test was given to a large sample of people in your country, so that your score today can be set against theirs. You get a report with a score per section and a conversation about what it means. It costs money and time, and that is exactly why the number means something.
Many people first meet such a test through Mensa. Mensa admits members who score in the top two percent on an approved test taken under supervision, either at one of its own test sessions or through a report from a qualified psychologist. A result from a website does not count there.
What an online test is missing
Four things, and each of them takes away part of the meaning.
- The norm group. A website seldom knows who did its tasks or under what conditions. A 128 on site A and a 112 on site B tell you nothing about yourself and everything about the difference between the two sites.
- Supervision. At home you look a puzzle up, do it together, or try it again. That is human, and it makes the result impossible to compare with anyone else's.
- Repetition. Anyone who takes the same test twice scores higher the second time, because the puzzles are familiar. Online, nothing stops you doing it five times and remembering the best score.
- The business model. Many sites let you take the test for free and charge for the result, or have a subscription waiting. Read what is free and what is not before you start, and look up the company behind the site.
None of that makes an online test useless. As a pastime, or to see which kind of puzzle comes easily to you, there is nothing wrong with it. Just do not write the number at the end down as your IQ.
When you need a real test
For a school, an employer, an assessment or a membership, only a test taken under supervision with a known norm group counts. In that case ask the organisation itself which tests it accepts, then look for a psychologist or a testing service that offers that test. Whatever you did online, you do not need to mention it there.
What the Skillido Brain Check is, and what it is not
Our free Brain Check is five games of 45 seconds each. Every game gives a game score from 0 to 100, and the average of the five is your Brain Check score. We set the scale for each game ourselves, based on what can be reached in that game, so that 50 is an ordinary round. That is our own calibration and not a norm group of the population. Once 50 people have completed the Brain Check, a percentile appears next to your score, set against the other players on this site, and within your age group once that group is large enough. How the scale is built, anchor by anchor, is on the facts page.
The Brain Check score is a game score: it says how you played these five games today, compared with other people who played them too, and it cannot be converted to an IQ. The test is free, needs no account, and shows all five scores right away. Nothing on the English pages is for sale.
Frequently asked questions
Is a free online IQ test reliable?
As a measure of your IQ, usually not, because the norm group and the supervision are missing. As a game, or as a first impression of which puzzles suit you, it can be fine.
What is a normal IQ score?
The average is 100 and about two thirds of people score between 85 and 115. That holds for a normed test under supervision; on a website it depends on the website.
Can I get my IQ tested for free?
A recognised test is almost always paid for, through a psychologist, a testing service or a Mensa test session. What is free is usually an exercise or a game.
Is the Skillido Brain Check an IQ test?
No. It is a free test of five games with a game score and, from 50 players onwards, a comparison with other players on this site.
Sources
- Mensa International, on the top two percent and its supervised test sessions: mensa.org
- Our own scale and the percentile rule: Skillido for AI
Who wrote this
This article was written by the Skillido editorial team. Skillido is a product of Next Day Online B.V. in Wilp, the Netherlands, registered with the Dutch Chamber of Commerce under number 08198136. We make a free test ourselves, and you may want to weigh that as you read.
If something here is wrong, write to hallo@skillido.com and a person will correct the text.
Written by the Skillido editorial team. Published on .