You may think of yourself as a relatively smart person, but like most people you likely don’t know exactly what is a high IQ or a good IQ score. Perhaps you’ve taken an officially proctored IQ test or an online test and received a score of 110. But, is 110 a high IQ? Is it an average IQ? 

Today, the two most popular IQ tests used by psychologists are the Stanford-Binet and Wechsler IQ tests. There are a number of versions of these tests that are administered based on your age range.

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IQ is one of the traditional measures of intelligence and many people are interested in questions like:

  • What is a good IQ?
  • What is a low IQ?
  • What is an average IQ?

The scale actually depends on which test you’ve taken as some tests have different scoring ranges than others. While the average for most tests is 100, the scales vary dramatically as to what constitutes extremely high or low intelligence. 

What IQ tests measure

An IQ test is not the only way to measure intelligence and cognitive ability, but the most popular tests have been studied extensively over the years and have statistically proven reliability in measuring for a high IQ. If you are about to take an IQ test, either as a requirement for something or just out of curiosity, then you can expect it to measure things like your visual and audio processing abilities. This can be done by seeing how well you understand a pattern that you are shown or how well you understand something that is played out loud for you to hear. An IQ test will also look at how fast you can process this information and how strong your short-term memory is.

Standard deviation of IQ scores

Popular intelligence tests like the Wechsler Adult Intelligence Scale have many subtests that provide scores for specific types of intelligence and then calculate a full scale intelligence score. That full scale intelligence score is usually what’s viewed as a person’s overall IQ. A standard deviations is a measure of a data set’s spread or variability. As mentioned above, scores mean different things based on the IQ test being used. The graph below shows the spread of scores for the popular Wechsler tests. 

IQ bell curve

The mean is 100 and the standard deviation of 15 means that 68% of test takers fall between a score of 85 and 115. The graph and scales change when using other tests like the Stanford-Binet (standard deviation 16) and the Cattell Culture Fair (standard deviation 24). As such, an IQ score of 120 on the Wechsler test would technically put you in a higher percentile than the same score on the other tests, with a more drastic difference between the Cattell Culture Fair result.

The range of IQ scores

Technically speaking, there is no upper limit of an IQ scale, while the lowest IQ test scores, of course, cannot go below zero. In reality, the lowest scores on the IQ test have been registered in the 40s, with a few possible outliers that could have gone as low as the 20s. As it stands, current IQ tests gather most everyone into a similar category once they start falling below 70.

Typically speaking, IQ tests tend to group people into one of seven categories (eight if you include geniuses as their own category). Differences from one category to the next tend to be minimal, while differences between the highest and lowest categories can be significant.

Under 67: Extremely low

A terribly contentious category, IQ testing isn’t actually used any longer as a benchmark as a determining factor for people with mental retardation or other mental disabilities. Instead, it is one of several possible indicators that an individual may not be legally competent to take care of himself or herself. Only about five percent of all people fall under this number, with the majority of those scoring somewhere between 50 and 67.

70-79: Borderline

Another controversial category, those with an IQ between seventy and seventy-nine are typically considered to be able to take care of themselves but may have some difficulty doing so. Those who remember the 1990s film Forrest Gump might recall that Forrest had an IQ of 75. Only about two percent of all people fall into this category, many of whom you might not expect at first glance. In fact, differentiating between IQs at all at the lower levels can be more a matter of social ability than anything else.

80-89: Low average

The vast majority of IQ scores – about seventy percent – will find this level as the bottom of the chart. Those with an IQ between eighty and eighty-nine are generally considered to be on the lower end of average. Remember, having an IQ in this range doesn’t mean that you aren’t clever – Steve Jobs was rumored to have an IQ that fell into this range. In most cases, having an IQ of this level means that formal education can be difficult but possible, while normal daily tasks are no more difficult at this range than they are at any other range.

90-109: Average

If you look around, this is where most of the people you’ll meet will fall. About fifty percent of all the people tested for IQ fall in here. People with this score find education no more or less difficult than most, nor do they tend to have any major intellectually-related problems taking care of themselves. It’s impossible to list famous people who might fall into this category, as at least half of them would show up here. If your IQ falls in this range, you’re in good company.

110-119: High average

The seventeen percent of individuals who fall into this category tend to be a little more intellectually gifted than others, but not by much. George Washington and JFK both fall in here, as does director Francis Ford Coppola. Those who fall into this range tend to find education a bit easier than their peers, though it has no real impact on activities of daily living. Once you’re at this point, you’re beginning to see changes in how information is processed rather than competency.

120-129: Superior

At this point, you start to see a noticeable difference from the average. Bill Clinton and George W. Bush both fall into this category, and some experts estimate that Leonardo da Vinci would have as well. Only about seven percent of all people fall into this rarified space.

130-139: Very superior

It’s hard to say that there’s really any differentiation in this group, as those with an IQ above 130 tend to make up a very small percentage of the population. This is the MENSA group, the top two percent of all IQ test takers. 

140 and above: Genius

The last major divide in IQ categories comes at 140, the point at which an individual is typically labeled a genius. Stephen Hawking, Albert Einstein, and numerous other famous figures fall in here. Typically, those with an IQ above 160 tend to have their IQs estimated rather than actually tested.

What is a good IQ score? Generally, anything above 85 means you’re at least average. This is just one way of measuring human intelligence, though, so it’s important to look at your IQ as a baseline.

Factors influencing a person’s score

There are some things that can affect a person’s score when they take an IQ test. High levels of anxiety can cause them to not do their best on the day of the test and would result in a lower score. Other things, like medical conditions, can also lower scores. For example, if someone has a hearing deficit or color blindness, they may score poorly on the test despite having a normal intelligence. While some of these factors may have a detrimental impact on IQ scores, people can improve their IQ over time. Human beings as a whole have continued to become smarter, which causes IQ tests to recalibrate results so that average scores retain the bell curve distribution above. This is known as the Flynn effect. If you’re interested, read up on our tips to improve your IQ score.

Highest IQ scores in history

There’s always some level of intrigue around famous people with high IQs, but in terms of raw intellectual horsepower, the people below are often brought up in discussions about people with the highest IQs.

  • Einstein: Most people correlate high IQs with Albert Einstein, but surprisingly he only scored in the 160-190 range. While these scores are still impressive, they are far from the highest out there. Einstein was a mathematician and physicist from Germany in the 1800’s. He received a Nobel prize for his work with light and the properties it has.
  • Christopher Michael Langan: This man was born in California and had a reported IQ score of 190-210. He had already learned to read by the time he was three and came up with a theory called the Cognitive-Theoretic Model of the Universe.
  • William James Sidis: This person has the highest scores ever recorded, ranging from somewhere around 250 up to the 300 range. (IQ tests can’t reliably score people that many standard deviations outside of the normal range.) This gifted individual was born in New York in 1898 and had learned six different languages by the time he was five. For reasons related to his family upbringing, he ended up focusing his life on politics instead of pursuing his education further.