Explore the IQ distribution interactively. Move the slider to see where any IQ score falls on the bell curve, with shaded percentile areas and classification bands.
Take our scientifically-designed IQ test to discover where you fall on the bell curve.
Take the IQ TestThe IQ bell curve, also called the normal distribution or Gaussian distribution, is a symmetrical probability distribution where most scores cluster around the mean (average) of 100. The standard deviation of 15 determines how spread out the scores are.
Key properties of the IQ bell curve: About 68% of people score between 85 and 115 (within 1 SD of the mean). About 95% score between 70 and 130 (within 2 SDs). About 99.7% score between 55 and 145 (within 3 SDs).
The shaded area on the curve above shows the proportion of the population that scores at or above the selected IQ value. The smaller the shaded area, the rarer the score.
The IQ bell curve (or normal distribution) is a symmetrical graph showing how IQ scores are distributed in the population. The peak is at IQ 100 (the average), and scores become increasingly rare the further they are from the center. About 68% of people score between 85 and 115.
Approximately 2.3% of the population has an IQ of 130 or higher. This corresponds to the 97.7th percentile on the standard IQ bell curve with a standard deviation of 15.
IQ follows a bell curve because intelligence is influenced by many independent genetic and environmental factors. According to the central limit theorem, when many independent variables contribute to an outcome, the result tends toward a normal (bell curve) distribution.