Average IQ Score by Age
How cognitive performance evolves from childhood through old age.
IQ by Age Group
Note: Scores are standardized relative to each age group's norm (not absolute). Raw cognitive scores differ from age-normalized IQ.
When does IQ peak?
Different types of intelligence peak at different ages. Fluid intelligence (speed, working memory, pattern recognition) peaks in your late teens to mid-20s. Crystallized intelligence (vocabulary, general knowledge, accumulated expertise) continues to grow well into your 50s and 60s.
How IQ is measured differently by age
IQ scores are always relative to your age group. A child aged 10 scoring 100 is performing exactly average for 10-year-olds — not average for adults. This is why IQ comparisons across generations or age groups must be interpreted carefully.
Can you improve your IQ as you age?
Research suggests cognitive training, physical exercise, adequate sleep, and continued learning can slow cognitive decline and even improve specific cognitive skills. The brain remains plastic throughout life, though the degree of plasticity decreases with age.
Frequently Asked Questions
At what age is IQ fully developed?
IQ stabilizes in late adolescence (around 16–18) for most people. Fluid intelligence peaks in the mid-20s, while crystallized intelligence continues developing through middle age.
Does IQ decline with age?
Processing speed and working memory tend to decline after 30, but vocabulary and general knowledge improve. The net effect varies by individual and lifestyle factors.
Is a child's IQ different from an adult's IQ?
Yes. Children's IQ is measured relative to other children of the same age. An IQ of 100 at age 8 means average for 8-year-olds, not for adults.
What is the best age to take an IQ test?
IQ tests are most reliable from age 6 upward. Adults in their 20s–40s typically produce the most stable and representative results.
How do you score for your age?
Take our free IQ test and get your age-adjusted score instantly.
Take the Free IQ Test