IQ to Percentile Calculator

Our IQ Percentile Calculator shows how your IQ score compares to the general population. Just enter your IQ score to see its percentile ranking, or enter a percentile to find the matching IQ score.

What is IQ?

IQ, or Intelligence Quotient, is a measure of cognitive ability relative to the general population. It is often used to assess mental capabilities like reasoning, problem-solving, and comprehension, and it offers an insight into a person’s intellectual potential and analytical capabilities. 

Originally, IQ was calculated by dividing a person’s mental age by their chronological age and then multiplying by 100. Modern IQ tests like CheckIQ evaluate a person’s performance relative to a representative sample of the population, often using a z-score to determine how far a score deviates from the average of 100. This score provides insight into how a person’s cognitive abilities compare to others, though it is only one measure within the broader field of human intelligence.

IQ scores are commonly associated with two key types of intelligence: fluid intelligence and crystallized intelligence. 

Fluid intelligence (also called Gf, where “G” stands for “general” and “f” for “fluid”) reflects the ability to think logically, solve novel problems, and absorb new information independently of prior knowledge. 

Crystallized intelligence (also called Gc, where “G” stands for “general” and “c” for “crystallized”), in contrast, builds on accumulated knowledge and skills, aiding tasks such as solving crosswords or playing vocabulary-based games like Scrabble. 

As outlined in the Neurobiology of Brain Disorders (2023), aging affects these two forms differently: fluid intelligence often declines over time, while crystallized intelligence can remain stable or even improve with age.

What is an IQ percentile?

An IQ percentile shows how your IQ score ranks compared to others. 

For instance, if your IQ falls in the 90th percentile, your score is higher than that of 90% of the population. This means you’re in the top 10%. Percentile-based indicator is helpful because it translates an IQ score into a comparative measure. It helps you understand how common or how rare your IQ score is compared to the general population.

What’s the difference between a percentile and a percentage?  

• A percentile shows how a score compares to others by ranking it within a group. For example, if your IQ is in the 90th percentile, it means you have a higher IQ score than 90% of people. Percentiles are useful for seeing where a score stands in relation to a population.
• A percentage, on the other hand, simply reflects a part of a whole out of 100. For instance, if you scored 80% on a test, you answered 80 out of every 100 questions correctly. Unlike percentiles, percentages measure accuracy or success directly and don’t provide information about how one’s score compares to others.

How can I find my IQ percentile?

To find your IQ percentile, you can start by taking an IQ test. You can take one with a psychologist for the most accurate results or use a trusted online IQ test. Once you have your IQ score, you can find your percentile in a few ways:

• IQ to percentile calculator: Use our easy-to-use calculator to see your percentile right away. Just enter your IQ score, and it will tell you how you rank compared to others. See the next section for more detailed instructions.
• IQ chart or table: You can also look at an IQ chart or table that shows IQ scores with matching percentiles. This gives you a quick look at how your score compares with the population. You'll find one later on in this article.

How do I use the IQ Percentile Calculator?

1. Enter your IQ score to view the equivalent percentile, or enter a percentile to find the corresponding IQ score.
2. Adjust the standard deviation if needed. Our tool defaults to a standard deviation of 15, which is used by most IQ tests, but it can be changed to 16 for tests like Stanford-Binet.
3. Check the results of the conversion: After calculating, the tool will display your IQ’s percentile along with a brief explanation, and you’ll see your score’s position on the IQ bell curve.

What is the standard deviation in IQ?

Standard deviation is a way to measure how much scores vary around the average. This helps create "standard scores" that show how someone’s score compares to the average (100 in IQ tests). 

Many widely recognized IQ tests today use a standard deviation of 15. This includes the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC), both of which measure cognitive abilities across verbal and performance domains. The Stanford-Binet Fifth Edition (SB5) also adopted a 15-point standard deviation to align with contemporary testing standards, as did Raven’s Progressive Matrices, which is particularly effective in assessing abstract reasoning.

The Cattell Culture Fair Intelligence Test (CCFIT) uses a standard deviation of 16, designed to measure fluid intelligence with minimal cultural bias, making it accessible across diverse backgrounds. Earlier versions of the Stanford-Binet Intelligence Scales (Edition I to Edition IV) also used a 16-point standard deviation before it switched to the more common 15-point standard deviation. 

Let’s see how the standard deviation you use affects your IQ. For instance, using a standard deviation of 15, an IQ test score of 115 (100 + 15 x 1) is one standard deviation above the mean. This corresponds to the 84th percentile, meaning it is higher than 84% of the population. This percentile-based interpretation helps illustrate how common or rare a particular IQ score is within the general population. It provides a structured way to measure cognitive abilities on a scale relative to the average.

How IQ Distribution and Charts Work

A Bell Curve Distribution

IQ scores are spread out in a bell curve, with most people scoring close to the average of 100. 

Using a standard deviation of 15, about 68% of people score between 85 and 115. Scores much higher or lower than this are rare—approximately 2.1% of people score above 130, and about 2.1% score below 70.

IQ Chart

An IQ chart helps you see where your score ranks among others by showing IQ scores and their percentiles. For example, an IQ of 130 is in the 98th percentile, meaning it’s higher than 98% of the population.

Understanding the IQ Scale and Classifications

What is the IQ scale?

The IQ scale is a general way to measure cognitive ability compared to the population, with an average IQ score set at 100. Most IQ tests use a standard deviation of 15, so scores generally fall within 15 points above or below the average, which helps categorize different IQ levels:

• Below 70: Extremely Low IQ
• 70–79: Borderline IQ
• 80–89: Below Average IQ
• 90–109: Average IQ (about 68% of people score here)
• 110–119: High Average IQ
• 120–129: Superior IQ
• 130 and above: Very Superior (high IQ)

For example, an IQ score of 130 is two standard deviations above the mean (130 = 100 + 2 x 15), placing it in the "Very Superior" range, which is typically in the top 2% of the population.

Common IQ classifications

While the IQ scale provides a basic range, different IQ tests (e.g., Wechsler, Stanford-Binet) use specific labels, or classifications, to help interpret scores. These classifications describe where an IQ score falls compared to the average. 

Here’s how major IQ tests label these ranges:

Wechsler (WAIS/WISC)

Here’s the classification for the commonly used Wechsler Adult Intelligence Scale (WAIS) and Wechsler Intelligence Scale for Children (WISC):

• 130 and above: Very Superior
• 120–129: Superior
• 110–119: High Average
• 90–109: Average
• 80–89: Low Average
• 70–79: Borderline
• Below 70: Extremely Low

Stanford-Binet (Fifth Edition)

The Stanford-Binet test uses different terminology, particularly with lower ranges where terms like "Impaired" or "Delayed" are used, reflecting its emphasis on developmental and intellectual disabilities. The higher ranges are labeled with terms like "Gifted" or "Highly Advanced."

• 140 and above: Very Gifted or Highly Advanced
• 130–139: Gifted or Very Advanced
• 120–129: Superior
• 110–119: High Average
• 90–109: Average
• 80–89: Low Average
• 70–79: Borderline Impaired or Delayed
• 55–69: Mildly Impaired or Delayed
• Below 55: Moderately Impaired or Delayed

Woodcock-Johnson

The Woodcock-Johnson scale follows a similar structure, with minor differences in terminology. For instance, it uses the term "Low" for scores in the 70–79 range and "Very Low" for scores below 70. The other categories, however, align with standard IQ classifications.

• 131 and above: Very Superior
• 121–130: Superior
• 111–120: High Average
• 90–110: Average
• 80–89: Low Average
• 70–79: Low
• Below 70: Very Low

As you can see, each classification system uses slightly different labels and ranges, but they all help make IQ scores easier to understand by describing the level of ability associated with each range

IQ Percentile Chart with Rarity

Below is an IQ-to-percentile conversion chart that shows the rarity of different test scores. For instance, if someone's IQ score is 140. It means they are in the 99.6th percentile and therefore have a higher IQ score than 99.6% of the population. This translates to roughly 1 in 200 people scoring this high, which is pretty rare. Similarly, an IQ of 135 corresponds to the 99th percentile. It means that less than 1% of the population have a higher IQ. 

This table is based on a standard deviation of 15 points. 

IQ Test Score	Percentile	Top X%	Rarity
100	50th	50%	1 in 2
104	60th	40%	1 in 2.7
108	70th	30%	1 in 3.3
110	75th	25%	1 in 4
113	80th	20%	1 in 5
115	84th	15.87%	1 in 6.3
119	90th	10.00%	1 in 10
125	95th	5.00%	1 in 20
129	97.5th	2.50%	1 in 40
130	97.7th	2.28%	1 in 44
131	98th	1.94%	1 in 52
135	99th	1.00%	1 in 100
139	99.5th	0.50%	1 in 215
140	99.6th	0.40%	1 in 250
147	99.9th	0.10%	1 in 1157
156	99.99th	0.01%	1 in 10,581

What is the top 1% IQ?

The top 1% IQ score is typically around 135 or higher. This means that someone with an IQ of 135 scores higher than 99% of the population.

What is the top 2% IQ?

An IQ of 131 places someone in the top 2% of the population. This is considered a high IQ and is often the minimum score required to join high-IQ societies.

What is considered a high IQ?

A high IQ is generally considered to be any score above 130. This level is achieved by about 2% of the population. A score above 130 usually aligns with the 98th percentile or higher, indicating that the individual performs better than 98% of the population.

What is considered a genius IQ?

A "genius" IQ is usually defined as an IQ of 140 or above. This is a rare score, seen in only about 0.4% of people, or about one in every 250. Some experts consider an IQ score of 145 or higher as the threshold for "genius-level" intelligence. This score is generally seen as an extremely high IQ and would place someone in the 99.9th percentile, meaning fewer than 1 in 1,000 people score this highly.

How rare is a 160 IQ?

An IQ of 160 is extremely rare and places someone in the top 0.003% of the population, or about 1 in 31,560 people. This level is often associated with extraordinary cognitive ability.

What IQ level qualifies for high-IQ societies?

High-IQ societies, like Mensa and Intertel, have minimum IQ thresholds for membership. For instance, Mensa typically requires an IQ in the 98th percentile or above, which corresponds to a score of around 130. Societies like the Triple Nine Society set even higher requirements, often in the 99.9th percentile (IQ around 146 or higher).

Many high-IQ societies also accept the scores obtained at standardized tests such as ACT, GRE, SAT and GMAT scores. For example, to get into Mensa, you’d need to show an IQ score of at least 130 but you could also provide your LSAT score, as long as it’s above 662 (95th percentile). 

We’ve built a tool to help you find which high IQ society you can join depending on your IQ, ACT, GRE, SAT and even GMAT scores. 

Frequently Asked Questions

How reliable are IQ tests?

Validated IQ tests administered by licensed professionals are generally reliable, with minimal measurement error. These tests are designed to accurately assess cognitive abilities, and they are widely considered among the most rigorously researched tools in psychology and psychometrics. They provide a scientifically backed approach to measuring your cognitive abilities, although they should be interpreted in the context of your individual’s unique strengths and characteristics.

For those preferring to do this online, make sure to pick a reliable IQ test. While many online tests can provide a general estimate, only well-designed, scientifically validated tests can offer a true measure of cognitive ability.

Is IQ a reliable estimate of intelligence? 

IQ scores provide a general indicator of cognitive ability and are highly reliable for measuring certain types of intelligence, especially fluid intelligence and crystallized intelligence, which involve reasoning and problem-solving. However, IQ scores alone do not capture the full range of human intelligence.

Howard Gardner’s theory of multiple intelligences suggests that intelligence isn’t just about IQ. It comes in many forms. Originally, he identified seven types of intelligence, but later he added two more, bringing the total to nine. Here’s a breakdown:

1. Linguistic Intelligence – Good with words, writing, and language.
2. Logical-Mathematical Intelligence – Great at problem-solving, logic, and working with numbers.
3. Spatial Intelligence – Able to visualize and work with shapes, objects, and spaces.
4. Musical Intelligence – Strong understanding of rhythm, tone, and music.
5. Bodily-Kinesthetic Intelligence – Skilled at using your body, like in sports or dance.
6. Interpersonal Intelligence – Good at understanding and working with others.
7. Intrapersonal Intelligence – Strong self-awareness and understanding of your own emotions.
8. Naturalistic Intelligence – Good at recognizing patterns in nature and connecting with the environment.
9. Existential Intelligence – Able to think deeply about life’s big questions, like the meaning of existence.

Note that Gardner’s theory has created interest among educators and psychologists, as it provides a framework for understanding the diverse strengths individuals possess. However, critics argue that some of these "intelligences" may be talents or personality traits rather than distinct forms of intelligence.

Moreover, factors like creativity, social skills, and unique talents are not directly measured by IQ tests but play a vital role in personal and professional success. Environmental influences, such as education, upbringing, and life experiences, also impact intelligence. This is why it’s quite difficult to measure it accurately.

Why might someone receive different IQ estimates from multiple tests?

IQ tests vary in their design, focus, and scoring methods, which can lead to differences in scores. For example, some tests, like the Wechsler, place more emphasis on verbal skills and memory, while others, like Raven’s Progressive Matrices, focus on visual and abstract reasoning. Even factors like how rested or calm a person feels, your mindset, or the environment where they take the test (e.g., noise or comfort level), can affect the performance. Because of these differences, professionally administered IQ tests that are standardized for accuracy provide the most consistent results.

Can preparation impact your IQ score? 

Yes, preparation can impact your IQ score. While it’s not possible to study exact IQ test questions, practicing with similar types of questions can help improve your performance. By working on typical IQ test question formats, you can develop problem-solving strategies and approach the test with greater confidence. This preparation isn’t about memorizing answers but about building skills in areas like memory, reasoning, and critical thinking.

Research supports this effect. For instance, a study by Australian researchers conducted over three years found that participants who regularly practiced problem-solving activities saw IQ increases of up to 15 points. Even short-term practice with strategic games, puzzles, or IQ test-style questions can improve cognitive flexibility and help boost IQ scores. Similarly, a Cornell study showed that cognitive training can enhance skills like working memory and processing speed, which are key to performing well on IQ tests. Finally, a study by Jaeggi et al., referenced by Sternberg (2008), shows that fluid intelligence can be improved with targeted training on working memory.

This improvement works much like athletic training. Just like athletes build different muscle groups, a well-prepared mind often achieves higher scores.

Does IQ change over time, especially in children?

Yes, IQ can change over time, particularly in children. While IQ tests aim to measure stable cognitive ability, children’s scores can vary due to growth, education, and life experiences. In early childhood, IQ scores are especially sensitive to factors like early education, nutrition, health, and family environment. Additionally, children with certain medical conditions, such as congenital heart disease, or developmental differences, like autism, may experience changes in IQ that reflect their unique needs and responses to early interventions.

For adults, IQ tends to be more stable, but factors like age, continued cognitive engagement, mental health, and overall well-being can still influence cognitive abilities over the lifespan.