IQ Score Chart — What Your IQ Score Means

IQ Score Scale & Classification

IQ scores are standardized so that the population average is always 100, with a standard deviation of 15 points. This means that most people — approximately two-thirds of the population — score between 85 and 115. The classification system below, based on the Wechsler scale, divides IQ ranges into descriptive categories that help you understand where your score falls relative to the general population.

It is important to note that IQ classifications are statistical descriptions, not value judgments. A score of 95 and a score of 105 are both considered "Average" and represent perfectly typical cognitive functioning. The boundaries between categories are conventions, not hard cutoffs — there is no meaningful cognitive difference between a score of 109 and 111, even though they fall in different classification bands.

These classifications are used worldwide by psychologists, educators, and researchers. The Wechsler Adult Intelligence Scale (WAIS) and the Stanford-Binet Intelligence Scales are the two most commonly referenced clinical IQ tests, and both use this general framework, though the exact labels may differ slightly between editions.

The IQ Bell Curve Explained

IQ scores in the general population follow a normal distribution, often called the "bell curve" because of its characteristic shape. This distribution is symmetric around the mean, meaning that scores above and below 100 are mirror images of each other. The bell curve is not an arbitrary choice — it emerges naturally from the fact that intelligence is influenced by a large number of independent genetic and environmental factors, each contributing a small effect.

The key parameters of the IQ bell curve are:

• Mean (average) = 100: By definition, the average IQ score is set to 100. This is a norming convention — raw test scores are converted to this standardized scale so that scores can be compared across different tests and time periods.
• Standard Deviation (SD) = 15: The standard deviation measures how spread out the scores are. On the Wechsler scale, one SD equals 15 IQ points. On the Stanford-Binet scale historically used an SD of 16, but modern versions have adopted 15 as well.

Understanding the standard deviation tells you how common or rare a particular IQ score is:

• 68% of people score between 85 and 115 (within 1 SD of the mean). This is the "average" range in practical terms.
• 95% of people score between 70 and 130 (within 2 SDs). Scores outside this range are statistically uncommon.
• 99.7% of people score between 55 and 145 (within 3 SDs). Scores beyond this range are extremely rare — fewer than 3 in 1,000 people score above 145 or below 55.

The bell curve has practical implications for interpreting your score. If you score 115, you are one full standard deviation above average — higher than about 84% of the population. A score of 130 puts you two standard deviations above average, exceeding roughly 98% of people. These percentile equivalents are discussed in detail in the next section.

One important point: the bell curve applies to populations, not individuals. Your personal IQ score reflects a snapshot of your cognitive performance at a particular time, under particular conditions. Test-retest reliability is high (typically r = 0.90+), but scores can vary by several points between sessions due to factors like fatigue, motivation, and testing conditions.

IQ Score Percentiles

A percentile tells you what percentage of the population scores at or below a given IQ. For example, being at the 75th percentile means you scored higher than 75% of people. Percentiles are often more intuitive than raw IQ numbers, because they directly answer the question: "How do I compare to everyone else?"

The following table shows the percentile equivalents for common IQ scores. These values are derived from the standard normal distribution with mean 100 and SD 15.

Notice how the percentile differences become more dramatic at the extremes. The difference between IQ 90 and IQ 100 is just 25 percentile points (25th to 50th), but the difference between IQ 130 and IQ 140 is only 1.6 percentile points (98th to 99.6th) — even though both represent a 10-point gap. This is because the bell curve is steepest in the middle and flattens toward the tails. Small IQ differences near the extremes represent much rarer cognitive distinctions.

What Is a Good IQ Score?

The concept of a "good" IQ score depends on context, but in general, any score of 110 or above is considered above average. At the 75th percentile, a person with an IQ of 110 outperforms three-quarters of the population on standardized cognitive measures. This level of cognitive ability is typically associated with strong academic performance, effective problem-solving in professional settings, and the capacity to quickly learn new skills and concepts.

A score of 120 or above places you in the "Superior" classification, exceeding approximately 91% of the population. People in this range often excel in intellectually demanding fields such as science, engineering, law, and medicine. They tend to be fast learners who can handle abstract concepts and complex reasoning with relative ease.

That said, IQ is only one dimension of cognitive ability. Research consistently shows that success in life, career, and relationships depends on many factors beyond IQ, including emotional intelligence, motivation, creativity, discipline, and social skills. A person with an IQ of 105 who is highly motivated and disciplined may achieve far more than someone with an IQ of 135 who lacks direction. Think of your IQ score as one data point in a much larger picture of who you are and what you can accomplish.

It is also worth noting that IQ scores are relative to the general population. Within specific professional or academic groups, the average may be considerably higher — graduate students, for instance, typically average around 115-125. A score of 110 is above the general average but may be below the average within a highly selective group.

Average IQ

The average IQ is 100 by definition. This is not a fixed physical measurement like height or weight — it is a statistical convention. When psychologists develop a new IQ test, they administer it to a large, representative sample of the population (the "norming sample") and calibrate the scoring so that the mean score of that sample equals exactly 100, with a standard deviation of 15.

Most people — approximately 68% of the population — score between 85 and 115, which is the "average" range in practical terms. Scoring within this range means your cognitive abilities are typical and well-suited to the demands of everyday life, including most occupations, educational programs, and social situations.

An interesting phenomenon called the Flynn Effect shows that raw IQ scores have been rising by about 3 points per decade across the 20th century in many countries. This does not mean people are getting "smarter" in some absolute sense — rather, it reflects improved nutrition, education, healthcare, and familiarity with abstract thinking. Because IQ tests are periodically re-normed, the average always returns to 100, even as raw performance improves over time.

Genius IQ Score

The term "genius" is used informally to describe exceptionally high intelligence, but there is no single agreed-upon IQ threshold for genius. In the Wechsler classification system, scores of 130 and above are classified as "Very Superior," and this is the cutoff used by many high-IQ societies, including Mensa (which requires a score at or above the 98th percentile, corresponding to IQ 130+).

Scores of 145 and above are often described as "genius" or "near-genius" level. At the 99.9th percentile, only about 1 in 1,000 people reaches this level. Historically, retroactive IQ estimates have placed notable thinkers like Albert Einstein, Leonardo da Vinci, and Marie Curie in the 160-190 range, though these are educated guesses based on their achievements rather than actual test scores.

It is essential to understand that extremely high IQ scores become increasingly difficult to measure accurately. Most IQ tests are designed and normed for the 70-130 range, where the majority of the population falls. Scores above 145-150 are extrapolations based on limited data and should be interpreted with caution. At these levels, the practical difference between a score of 150 and 160 is difficult to define and may not be reliably measurable.

How Our Test Calculates Your IQ

At IQgenio, we use a combination of three scientifically-established approaches to calculate your IQ score: Computerized Adaptive Testing (CAT), Item Response Theory (IRT), and the Cattell-Horn-Carroll (CHC) Theory of cognitive abilities.

Computerized Adaptive Testing means the test adjusts its difficulty in real-time based on your responses. When you answer a question correctly, the next question becomes harder; when you answer incorrectly, it becomes easier. This adaptive process converges on your true ability level more efficiently than traditional fixed-length tests, providing a more accurate estimate in fewer questions.

Item Response Theory is the statistical framework that powers the scoring. Unlike simple percent-correct scoring, IRT considers both how many questions you answered correctly and the difficulty level of those questions. Getting a hard question right contributes more to your estimated ability than getting an easy question right. This approach produces more precise and fair scores.

CHC Theory provides the blueprint for what we measure. Rather than treating intelligence as a single number, CHC Theory identifies multiple broad cognitive abilities — fluid reasoning, working memory, processing speed, visual-spatial processing, crystallized intelligence, quantitative reasoning, and long-term retrieval. Our test evaluates all seven domains, giving you both an overall IQ score and individual domain scores.

Ready to see your results? Take our free adaptive IQ test — you will receive your overall IQ, percentile ranking, and a breakdown across all 7 cognitive domains. To learn more about our methodology, visit our About page.

How to Improve Your IQ Score

While your baseline intelligence is influenced by genetics, research shows that cognitive abilities can be improved through targeted training and lifestyle choices. Neuroplasticity — the brain's ability to form new neural connections throughout life — means that deliberate cognitive exercise can genuinely enhance mental performance.

Key strategies for improving your cognitive abilities include regular brain training that targets specific domains (pattern recognition, working memory, processing speed), maintaining physical fitness (aerobic exercise increases blood flow to the brain and promotes neurogenesis), getting adequate sleep (memory consolidation occurs during deep sleep), and engaging in continuous learning (reading, learning new skills, and solving novel problems).

Our brain training program offers 306 targeted exercises across 6 categories, designed to strengthen the same cognitive domains measured by our IQ test. For a comprehensive guide on evidence-based strategies, read our detailed article on how to improve your IQ.