Average IQ by Age, Explained

"What's the average IQ for my age?" is one of the most common questions people ask — and the answer surprises most of them. Because of how IQ tests are built, the average is 100 at every age. Let's unpack why, and what actually changes under the hood as you get older.

Why the average is always 100

IQ scores are age-adjusted. When a test is calibrated, your raw performance is compared to other people in your age group, then mapped onto a scale where that group's average is set to 100. So a sharp 70-year-old and a sharp 25-year-old can both score 130 — each is being compared to their own peers, not to each other. The number is always relative.

What actually changes with age

Even though the average stays pinned at 100, the raw abilities underneath shift over a lifetime — and in opposite directions:

• Fluid intelligence (raw problem-solving and processing speed) tends to peak in the late teens to late twenties, then gradually eases.
• Crystallised intelligence (vocabulary, knowledge, judgement) keeps climbing well into middle age and often holds steady far longer.
• This is why older adults often reason more wisely even as younger adults solve novel puzzles faster — different strengths, different seasons.

The Flynn effect: a twist across generations

There's a famous wrinkle called the Flynn effect — average raw scores rose substantially across the 20th century, generation after generation, likely due to better nutrition, education and more abstract thinking in everyday life. Tests get re-standardised periodically to keep the average at 100, which is partly why comparing scores across decades is tricky.

Your age doesn't change what a "good" score is — 100 is average whether you're 18 or 80. What matters is your percentile among your peers.

The bottom line

Don't get hung up on finding a different "target number" for your age. Focus on your percentile — the share of people you scored higher than — and on keeping your mind active, because staying mentally engaged is strongly linked to protecting cognitive sharpness as you age.

Curious where you land right now? Take the assessment, get your percentile, and come back any time to see how you're tracking.