The average IQ is 100. IQ tests are normed so that the mean of the population is 100 and the standard deviation 15, which means half of people score below 100 and half above.
What is a normal IQ?
About half of people score between 90 and 109, the range usually called average, and two in three between 85 and 115.
Average IQ in the UK and the US
Tests normed in the UK set the UK average at 100, and tests normed in the US do the same for the US. Comparing countries on these scores mixes different tests and samples, so headline rankings of average IQ by country are not reliable.
Average IQ by age
Because each age group is compared with itself, the average IQ is 100 at every age. What changes is raw performance: fluid reasoning peaks in the early twenties and declines slowly, while vocabulary and knowledge keep growing into later life.
Why the average is reset
Raw scores rose about 3 IQ points per decade during the 20th century, the Flynn effect. Tests are re-normed every 15 to 20 years so that 100 keeps meaning “average today”.
Average IQ for men and women
Average IQ scores for men and women are practically the same. Some studies find slightly more men at both extremes of the distribution, but the size and causes of that difference are still debated.
Average IQ by country
National averages exist, but they are hard to compare: the samples are often small, tests differ, and schooling, health and test familiarity vary a lot between countries. Treat any league table of countries with caution. Modern tests are normed so that the average adult in the reference population scores 100.
What can change your score on the day
- Sleep and tiredness lower attention and working memory.
- Anxiety about the test can cost several points.
- Practice: taking the same test again raises the score without raising ability.
- Language: verbal tasks penalise people tested outside their first language.
That is why every Animi result shows a range, not a single number. Take the free IQ test rested, once, and read the interval.
What is a normal IQ, and what is a good IQ?
A normal or average IQ is 90 to 109, the range where half of the population scores. About 68% of people fall between 85 and 115. A “good” IQ depends on the comparison: 110 to 119 is above average, 120 to 129 is high, and 130 or more is very high.
Frequently asked questions
Is 110 above average?
Yes, slightly: it is higher than about 75% of people.
Is 100 a good IQ?
Yes. 100 is exactly average: half of people score higher and half lower.
Do men and women have different average IQs?
No meaningful difference in averages. Some studies find slightly more variability among men.
What is a normal IQ?
Between 90 and 109; half of the population scores in that range.
What is a good IQ score?
Anything from 110 is above average; 120 or more is high and 130 or more is very high.
Sources
- Neisser, U. et al. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51(2), 77–101.
- Plomin, R. & Deary, I. J. (2015). Genetics and intelligence differences: five special findings. Molecular Psychiatry, 20(1), 98–108.
- Ritchie, S. J. & Tucker-Drob, E. M. (2018). How much does education improve intelligence? A meta-analysis. Psychological Science, 29(8), 1358–1369.
- Wechsler, D. (2008). WAIS-IV: Technical and interpretive manual. Pearson.