Understanding the Basics of IQ
What is IQ?
Distribution of IQ in the world population according to the Gaussian curve (in %)
The IQ (Intelligence Quotient) is a measure of intelligence designed to categorize the population. In this classification, 98% of people have scores between 70 and 130, and 50% are between 90 and 110.
The farther an IQ score deviates from the average of 100, the fewer people will have that score. Only 2% of the population scores below 70 or above 130. This is illustrated by the Gaussian curve with a standard deviation of 15.
What is the purpose of knowing your IQ?
Knowing your IQ can help you better understand yourself and recognize differences (or similarities) with others, especially if your score is significantly lower or higher than average. It can explain certain strengths or difficulties in social interactions, professional activities, or educational settings.
An IQ score should be taken as an indicator among other aspects of personality (motivations, values, etc.) rather than a definitive conclusion. IQ is just one indicative factor; it does not define your entire identity, which also includes many other facets (personality, motivations, values, and so on).
What is a gifted person?
“Gifted” individuals have an IQ above 130. They typically find intellectual activities easier. Common traits of gifted individuals include:
- Strong curiosity and a thirst for learning
- High perfectionism
- Occasionally obsessive interest in certain topics
- Often invisible hypersensitivity
- Great capacity for attention and concentration
What is a person with a very low IQ?
People with an IQ below 70 may experience greater difficulties in intellectual and social activities, despite their willpower and efforts. They may also face challenges with social behaviors.
Can my IQ change over time?
IQ score by age group
Yes, our data indicate that age influences IQ. An individual’s IQ peaks between 18 and 39 years of age, then gradually decreases.
Other factors, such as dietary habits and engaging in intellectually stimulating activities (like playing chess), can also impact IQ.
A 2025 study found that children with healthier eating habits scored higher on IQ tests than their peers.
Another 2022 study showed that children who played chess at school improved their IQ scores.
What is the method of this IQ test?
This IQ test is inspired by Raven’s Matrices (created by psychologist John Carlyle Raven in 1936). In each question, the candidate completes a series using logic. This method measures reasoning ability, the capacity to handle complexity, and to recognize and reproduce patterns.
This technique makes it possible to fairly assess IQ across different countries and languages, making it a good option for an international IQ test.
What is the most reliable IQ test?
For an IQ test to be considered reliable, it must produce results following a Gaussian distribution (mean of 100, standard deviation of 15) when administered to a representative sample of the population.
We have published a study showing the reliability of the International IQ Test, based on a representative sample of the global population, which revealed an average IQ of 100 and a standard deviation of 15.
To our knowledge, we are the only team to have refined an IQ test algorithm to this level of precision, so we consider our test to be the most reliable IQ test on the internet.
However, these results should be taken as indicative. This test does not replace an in-person psychological examination or other assessment methods besides Raven’s matrices. That is why we do not issue official IQ certificates.
What is the official IQ test?
There is no single, universally recognized official IQ test. Various methods exist, but none enjoys unanimous acceptance.
However, this IQ test was the very first to be called the “International IQ Test.” From its launch in 2018, it has been translated into multiple languages to expand its global database and perfect its IQ measurement algorithm, striving to be as reliable as possible.
Our annual ranking of IQ by country is frequently cited by online journals and indirectly demonstrates the test’s reliability via the year-to-year stability of these national average IQ scores.
How long does this test take?
The test takes about 20 to 30 minutes on average. While completion time is factored into your final score, its overall impact is minor. Simply focus on solving the problems.
What is the maximum IQ score of the test?
The highest IQ score you can achieve on this test is 142.
When can I retake the IQ test?
Please wait at least one year before retaking this IQ test to avoid biasing your results. The longer you wait, the more reliable the outcome. Usually, your first result is the most accurate.
Is this IQ test free?
Yes, this is a free IQ test. After submitting your information, you can instantly access your results at no cost by clicking the link at the bottom of the page or on the logo at the top left. Payment is optional and gives access to a correction report showing which answers were correct or incorrect.
Do you offer a subscription?
No, this site does not offer subscriptions. Payment for additional features is a one-time transaction without hidden fees. When you purchase extras (like the correct and incorrect answer report), it is a single transaction. There are no subscriptions or hidden charges.