Average IQ for a teenager, ages 13 to 18

Every row says 100 because every age has its own norms. A typical 18-year-old solves much harder problems than a typical 13-year-old, but each is compared only with their own age group. At 16 a psychologist can choose a children's or an adult test.

The average IQ of a 13, 14, 15, 16, 17 or 18-year-old is 100. A given score also means the same thing at every one of those ages, because each age is scored against its own peers. Here is one worked example for each age.

An IQ is not a raw score. When a test is built, the publisher gives it to a large sample of people of each age. Your raw score is then compared only with people your own age, and converted to a scale where the middle of that age group is 100 and the standard deviation is 15.

That is why a 10-year-old and an 18-year-old can both have an IQ of 100 while solving very different problems. The number tells you where someone stands among their peers, not how much they know. It also means that there is no such thing as an average IQ that rises with age.

Teenage IQ scores reflect a period of significant cognitive development. Fluid intelligence peaks during late adolescence, while crystallized intelligence continues to grow. The average IQ for teenagers is 100 (age-normalized), but individual scores become more stable and predictive of adult IQ during this period.

• Fluid intelligence (abstract reasoning, pattern recognition) approaches its peak during late adolescence
• Prefrontal cortex development continues through the mid-20s, affecting executive function and decision-making
• Academic performance correlates moderately (r ≈ 0.50) with IQ during teenage years
• Socioeconomic factors continue to influence IQ development, though genetic factors become increasingly dominant

During the teenage years, fluid intelligence approaches its lifetime peak (typically around ages 18-25). Crystallized intelligence accelerates rapidly due to formal education and broader life experiences. This is why teenagers often outperform younger children on tasks requiring abstract reasoning.

How people this age are tested

Teenagers can be assessed with either the WISC-V (ages 6-16) or WAIS-IV (ages 16+). Motivation is a significant factor: unmotivated teenagers may score below their true ability. Test anxiety is common and can be mitigated with proper preparation. Online IQ tests lack the standardization and clinical oversight of formal assessments.

The average above is a statistic, not a test. The IQ test for teens and teenagers page explains how the LifeScore test works for this group: the same 25 puzzles for everyone, not age-normed, and honest about what the number can show. Pick the page that matches the age you have in mind.

Two tools go with this page. The average IQ by age calculator turns a score into a percentile for an age group. The mental age calculator shows the old ratio formula and why modern tests dropped it.