You can test your IQ through a professionally administered exam given by a psychologist, through a supervised test offered by organizations like Mensa, or through online assessments, though only the first two produce scientifically meaningful scores. The method you choose depends on why you want the number and how much accuracy matters to you.
What an IQ Test Actually Measures
IQ tests measure a range of cognitive abilities: pattern recognition, spatial reasoning, verbal comprehension, working memory, and processing speed. Your score is calculated relative to the general population, with 100 set as the average. About 68% of people score between 85 and 115. The number itself isn’t a fixed trait. It can shift modestly depending on the test, the day, your stress level, and even how much sleep you got the night before.
The score is most useful in specific contexts: identifying learning disabilities, qualifying for gifted programs, or understanding cognitive strengths and weaknesses. Outside those situations, it’s an interesting data point but rarely changes what you should do with your life.
Professional Testing Through a Psychologist
The most accurate way to measure your IQ is a clinical assessment administered one-on-one by a licensed psychologist. The two most widely used tests for adults are the Wechsler Adult Intelligence Scale (WAIS) and the Stanford-Binet Intelligence Scale. For children, psychologists typically use the Wechsler Intelligence Scale for Children (WISC), the Woodcock-Johnson Tests of Cognitive Ability, or the Kaufman Assessment Battery for Children.
These tests take one to three hours and involve a variety of tasks, not just answering multiple-choice questions. You might arrange blocks to match a pattern, repeat sequences of numbers backward, define vocabulary words, or solve visual puzzles under time pressure. The psychologist scores each subtest and produces a full-scale IQ along with breakdowns of specific abilities.
Professional testing typically costs between $200 and $600 for a basic IQ evaluation, though a comprehensive neuropsychological assessment that includes IQ as one component can run $1,000 to $3,000 or more. Health insurance sometimes covers testing when a doctor refers you for a clinical reason, such as evaluating a learning disability or cognitive decline, but it rarely covers testing done purely out of curiosity. To find a provider, search for psychologists in your area who offer psychoeducational or neuropsychological evaluations.
Take a Supervised Test Through Mensa
If you want a legitimate score without the cost of a full clinical evaluation, American Mensa offers supervised testing. You need to score in the top 2% of the population (roughly an IQ of 132 or higher on most scales) to qualify for membership, but the test itself gives you a real, proctored result regardless of whether you hit that threshold.
If you’re 14 or older, you can take a supervised, standardized test administered by a certified volunteer or at one of more than 400 approved private testing centers across the country. The test fee is modest compared to clinical evaluations. You can also skip the test entirely and submit qualifying scores from prior standardized tests you’ve already taken, including the SAT, Stanford-Binet, or CogAT (Cognitive Abilities Test). Many people already have a qualifying score sitting in their records from childhood gifted testing or college entrance exams.
For children under 14, Mensa encourages parents to submit evidence of past testing rather than having the child sit for a new exam.
Why Online IQ Tests Are Unreliable
Free online IQ tests are everywhere, and most of them are essentially meaningless. They haven’t been validated against clinical instruments, they aren’t administered under controlled conditions, and many are designed primarily to generate web traffic or sell you a detailed “report” after you finish.
How unreliable are they? One neuroscientist tested several popular online IQ tests by answering every single question completely at random and still received scores classified as “very superior” and “superior.” If clicking randomly produces a genius-level result, the test isn’t measuring anything real. These sites tend to skew scores high because a flattering result makes you more likely to share it on social media or pay for the premium version.
That said, some well-designed online assessments can give you a rough sense of your cognitive strengths. Just treat any score from an unproctored internet quiz as entertainment, not data. If the number matters for any practical purpose, whether that’s school placement, a disability evaluation, or personal clarity, you need a real test.
Cognitive Screening Tools
If you’re less interested in a single IQ number and more curious about how your brain performs across different tasks, cognitive screening tools offer another option. The NIH Toolbox, developed by Northwestern Medicine investigators, is an iPad app that measures cognitive, motor, sensory, and emotional function through more than 50 tests. It uses computer adaptive testing, meaning the app adjusts question difficulty in real time based on your responses, which makes the assessment both faster and more precise. Some tests take five minutes or less.
The NIH Toolbox is designed for clinical and research use, so your doctor would be the one administering it rather than you downloading it at home. It’s particularly useful for tracking cognitive changes over time or screening for neurological conditions, and it works for people ages 3 to 85 and older. It won’t hand you a traditional IQ score, but it gives a detailed picture of how your brain handles specific tasks like memory, attention, and processing speed.
Which Option to Choose
Your best path depends on your goal. If you need an IQ score for a school placement, disability accommodation, or workplace evaluation, get professional testing through a psychologist. The detailed subtest scores are often more useful than the overall number, and only a licensed professional can produce a report that institutions will accept.
If you’re curious where you fall and want a legitimate result without spending hundreds of dollars, Mensa’s supervised testing is a solid middle ground. You’ll get a real, standardized score in a controlled setting. Check whether you already have a qualifying score from a past standardized test before scheduling a new one.
If you just want to scratch an itch on a Saturday afternoon, an online test will give you something to think about. Just know the number it produces says more about the website’s algorithm than about your actual intelligence.