What Is a Normal IQ Score?
A normal IQ score ranges from 85 to 115, representing the middle 68% of the population on a standardized bell curve with a mean of 100 and standard deviation of 15.
Understanding Average IQ
The concept of "normal" in IQ testing is statistically defined. IQ tests are calibrated so that the median score is always 100. The standard deviation of 15 means that most people (about 68%) fall between 85 and 115. Approximately 95% of the population scores between 70 and 130.
IQ Score Percentiles
IQ 8516th percentile
IQ 9025th percentile
IQ 9537th percentile
IQ 10050th percentile
IQ 10563rd percentile
IQ 11075th percentile
IQ 11584th percentile
Factors That Influence IQ
IQ is influenced by both genetic and environmental factors. Twin studies suggest genetics account for 50–80% of IQ variance in adults. Environmental factors include prenatal health, nutrition, education quality, socioeconomic status, and cognitive stimulation during childhood.
Frequently Asked Questions
A normal IQ score falls between 85 and 115, which encompasses approximately 68% of the population. The exact center is 100, which is the designed average for all standardized IQ tests. Scores within this range indicate typical cognitive functioning.
An IQ of 110 is above average and places you in approximately the 75th percentile—meaning you scored higher than 75% of the population. While not classified as 'gifted' (which starts at 130), an IQ of 110 indicates strong cognitive abilities and correlates with academic and professional success.
IQ scores between 70 and 84 are classified as below average. About 14% of the population falls in this range. Scores below 70 may indicate intellectual disability and typically warrant professional evaluation, though a single test score should never be used as the sole diagnostic criterion.
Research consistently shows that education positively influences IQ scores. Each additional year of schooling is associated with an increase of 1–5 IQ points. Education particularly boosts crystallized intelligence (acquired knowledge) while also training working memory and reasoning skills that contribute to fluid intelligence.
Absolutely. IQ explains only about 25% of the variance in career success. Factors such as emotional intelligence, perseverance, creativity, social skills, and opportunity play equally or more important roles. Many highly successful individuals have average IQ scores but excel through dedication, expertise, and interpersonal skills.