Understanding the Basics of IQ
What Is IQ?
IQ (intelligence quotient) is a standardized measure intended to compare general cognitive ability within a population.
In a typical IQ distribution, about 98% of people score between 70 and 130, and about 50% score between 90 and 110.
The farther a score is from the average of 100, the fewer people fall in that range. That’s why only about 2% of the population scores below 70 or above 130.
This is illustrated by the bell curve with a standard deviation of 15.
IQ distribution in the global population (bell curve, %)
What’s the point of knowing your IQ?
Knowing your IQ can help you understand your strengths and challenges and put differences (or similarities) with others into perspective—especially if your score is well below or above average.
It may also help explain certain patterns you notice in relationships, work, or school.
IQ is best viewed as one data point—not a definitive judgment. It doesn’t capture the full picture of who you are, including personality, values, motivations, and other strengths.
What does it mean to be gifted?
In IQ testing, “gifted” often refers to an IQ above 130. People in this range may find certain cognitive tasks easier. Common traits can include:
- Strong curiosity and a drive to learn
- High standards and perfectionism
- Deep focus on specific interests
- Heightened sensitivity that may not be obvious to others
- Strong ability to concentrate
What does a very low IQ mean?
People with an IQ below 70 may face more challenges with certain learning, problem-solving, and day-to-day cognitive tasks, even when they work hard and stay motivated.
They may also experience challenges in some social situations.
Can my IQ change over time?
Yes—our analysis of test results suggests that age is associated with IQ scores. Scores tend to peak
between ages 18 and 29, then gradually decline.
Other factors—like diet and regular mentally stimulating activities (for example, chess)—may also be associated with IQ differences.
A 2025 study found that children with healthier eating habits scored higher on IQ tests.
A 2022 study found that school-based chess programs were associated with increases in children’s IQ scores.
Average IQ score by age group
What method does this IQ test use?
This test is inspired by Raven’s Progressive Matrices (developed by psychologist John Carlyle Raven in 1936).
For each question, you complete a visual pattern using logic. This format helps measure reasoning, complexity handling, working memory, and pattern recognition.
Because it relies on nonverbal puzzles, it’s well-suited for an international audience across countries and languages.
How reliable is this IQ test?
The International IQ Test’s global database—containing over 16 million results—has made it possible to develop an IQ-scoring model based on large-scale data.
A standardization report, available here, used an effective sample of 66,032 results collected over three consecutive years (2020, 2021, and 2022).
It applied anti-bot and duplicate filtering and calibrated results to the global population.
The report confirmed a worldwide mean IQ of 100 with a standard deviation of 15.
A separate report examined how strongly the test scores relate to the general intelligence factor (g), finding a g-loading of ~0.943.
This result was stable across two consecutive years with samples of 50,000 test-takers per year.
This supports the idea that the test is measuring cognitive ability.
What’s the most reliable online IQ test?
For an online IQ test to be considered reliable, it should:
- produce a bell-curve distribution (mean 100, standard deviation 15) when standardized on a sample calibrated to the global population
- measure at least one broad cognitive ability (high g saturation)
Based on the reliability report (mean 100, SD 15; g-loading ~0.943), the International IQ Test appears to be among the more reliable online options.
Is there an official IQ test?
There isn’t one single, globally recognized “official” IQ test. Multiple approaches exist, and no single method is universally accepted as the standard.
That said, this was the first test to use the name “International IQ Test.” Since launching in 2018, it has been translated into many languages to expand the international dataset and refine the scoring model over time.
Our annual ranking of average IQ by country is cited by online media, and country averages tend to remain relatively stable year to year.
What is the official website for the International IQ Test?
international-iq-test.com is the official website for the “International IQ Test,” online since 2018.
You can verify how long a website has been online using the Wayback Machine (archive.org).
This IQ test has already been taken by over 16 million people and has been standardized using psychometric criteria.
How long does this test take?
The test typically takes about 20–30 minutes. Time can have a small effect on results, but it’s minimal—focus on solving the problems as accurately as you can.
What’s the maximum IQ score on this test?
The highest possible score on this test is 142.
When can I take the test again?
To avoid practice effects that can bias results, we recommend waiting at least a year before retaking the test.
In general, the longer you wait, the more reliable your next result will be. Your first score is usually the most reliable.
Is this IQ test free?
Yes. At the end of the test, you can view your IQ score right away—for free, with no payment required.
What’s included in the free results?
Your free results include your IQ score plus personalized statistics comparing your score with the population across different benchmarks (for example, the general population and your age group).
What are the limitations of this IQ test?
Online IQ tests have clear limitations:
- Test-takers have internet access (people without access are underrepresented in the data)
- This test does not measure every facet of intelligence—only abilities assessed by Raven-style matrices
- Online IQ tests are not diagnostic and do not replace an in-person psychological evaluation
Even so, the International IQ Test can be a useful, informative benchmark—specifically for the type of general intelligence measured by Raven-style matrices—relative to the global internet-connected population
(which continues to grow; as of 2025, about 74% of the world’s population has internet access).