IQ Percentile Calculator
Translate an IQ test result into a percentile to understand how it compares with the general population.
How to Use This Calculator
Obtain a standardized IQ score
Use scores from validated assessments like WAIS, WISC, Stanford–Binet, or modern online adaptive tests.
Enter the score
Most modern IQ tests use a mean of 100 and standard deviation of 15. If your test uses different scaling, convert before entry.
Interpret the percentile
Percentile shows how many people scored lower. Combine results with educational, occupational, or psychological evaluations for context.
Formula
Z-score = (IQ − 100) ÷ 15
IQ scores are standardized to form a bell curve with mean 100 and standard deviation 15. Approximately 68% of people score between 85 and 115.
About IQ Percentiles
IQ percentiles express where a score falls within the population. For example, the 90th percentile means the individual scored higher than 90% of test-takers.
Psychologists use IQ tests to assess learning needs, intellectual giftedness, or cognitive challenges. However, IQ does not measure emotional intelligence, creativity, motivation, or social skills—all vital for success.
Common IQ ranges
- 130+: Gifted
- 120–129: Very superior
- 110–119: Superior
- 90–109: Average
- 80–89: Low average
- 70–79: Borderline
- <70: Extremely low
Frequently Asked Questions
Are online IQ tests reliable?
Some adaptive online tests correlate well with standardized assessments, but supervised testing provides the most accurate results.
Can IQ change over time?
IQ is relatively stable in adulthood but can vary in childhood as the brain develops. Education and practice can improve test performance.
Does percentile equal probability?
Percentile indicates the percentage of people who scored lower. It is not the probability of future outcomes.
What if my score feels inaccurate?
Fatigue, anxiety, or testing environment can affect results. Retesting or consulting a psychologist can provide clarity.
Is IQ the same as intelligence?
IQ is one measure of cognitive ability, but intelligence is multifaceted. Creativity, emotional awareness, and practical skills also matter greatly.