The IQ Scale and Range Chart: Every Score, Level and Percentile
A complete reference for IQ scores from 55 to 160 — what each range means, how percentiles work, and where any score falls on the bell curve. Free, no sign-up needed.
The Full IQ Scale Chart
Every IQ range at a glance: the score band, its percentile under the standard scale, and what that level means in practice.
| IQ range | Percentile | SD band | Classification | What it means |
|---|---|---|---|---|
| 130+ | 98+ | ≥ +2 SD | Very Superior | Around the Mensa entry line (top ~2%). Rare — most people meet only a few individuals at this level. |
| 120–129 | 91–98 | +1.33–+2 SD | Superior | Common in postgraduate cohorts and demanding analytical work. |
| 110–119 | 75–91 | +0.67–+1.33 SD | High Average | Typical of many university graduates and professional roles. |
| 90–109 | 25–75 | ±0.67 SD | Average | The middle half of everyone. All standards are defined relative to this band. |
| 80–89 | 9–25 | −1.33–−0.67 SD | Low Average | Still fully within the normal range — not a label of any deficiency. |
| 70–79 | 2–9 | −2–−1.33 SD | Borderline | Professionals may suggest a fuller assessment; online tests are least reliable at the extremes. |
| < 70 | 1–2 | ≤ −2 SD | Extremely Low | Online testing cannot measure this range reliably — a professional evaluation is the appropriate path. |
Percentiles follow the Wechsler convention: mean 100, standard deviation 15. Our free IQ test converts results onto this same scale definition — the conversion is mathematical, not a clinical norming.
What the IQ Scale Actually Measures
An IQ score is a position, not a quantity. The scale is defined so that 100 is always the exact middle of the population and 15 points equals one standard deviation — a fixed step size. A score of 115 does not mean you have “115 units” of intelligence; it means you scored higher than about 84% of people on this scale.
Modern assessments are built on the Cattell–Horn–Carroll (CHC) framework, the same theory underlying professional instruments like the WAIS. Online tests sample a narrow slice — mostly fluid reasoning — so treat any single score as one estimate, not a verdict.
IQ Levels and Their Classifications
The labels in the chart — Superior, High Average, Borderline and so on — come from the Wechsler classification tradition. They describe how common a score is, not what a person can or cannot do.
Two people with the same score can differ widely in specific strengths. A profile view (like the category breakdown in our free IQ test) says more about how someone thinks than the total alone.
IQ Percentile Calculator
Enter any IQ score to see its percentile on the standard scale, its classification, and how rare it is.
Derived from the scale definition (mean 100, SD 15), clamped between 0.5 and 99.5 — the same conversion our test uses. Don't know your score? Take the free test
The Bell Curve and Standard Deviation
IQ scores form a normal distribution. Because the standard deviation is fixed at 15, the population clusters around 100 in predictable proportions — this is why the same score means the same rarity everywhere on the scale.
Frequently Asked Questions
Have another question? Let us know.
What is a good IQ score?
By definition, 100 is the middle of the scale — half of all people score below it. Scores of 110–119 are higher than about 75% of people, and 120+ beats roughly 9 in 10. “Good” depends on context: most jobs, studies and everyday reasoning sit comfortably inside the average band.
Is 130 the entrance score for Mensa?
On the most common scale (mean 100, SD 15), 130 is roughly the traditional Mensa entry line — about the top 2%. Each national Mensa branch administers its own supervised test with its own criteria, so check your local branch for exact requirements.
Can your IQ score change over time?
A score carries a genuine margin of error — typically ±7 points for online tests — and practice effects can inflate a retake by a few points. The underlying ability is fairly stable in adulthood, but a single online result should be read as an estimate with a range, not a fixed number.
How accurate are free online IQ tests?
They are screening estimates, not clinical assessments. They sample a narrow slice of cognition (mostly fluid reasoning) under uncontrolled conditions. They are reasonable for curiosity and self-reflection — and if a result prompts deeper questions, the right next step is a licensed psychologist, not another website.
What is the average IQ by country or age?
The scale defines 100 as the average by construction. Country-level comparisons (like our global IQ rankings) come from research datasets sampled differently than online tests, and clinical practice adjusts norms by age — a raw online score should not be compared across ages or countries as if it were a normed assessment.
Curious where you actually fall?
Take our free 47-question IQ test — instant score, percentile and category breakdown. No sign-up, no hidden paywall.
Take the free IQ testThis test is for educational and self-reflection purposes only. It is not a diagnostic tool. If you are experiencing mental health concerns, please consult a qualified healthcare professional.
