What does an IQ of 120 mean?
Above the central range on the reference scale, at approximately percentile 90.88.
- IQ score
- 120
- Percentile
- 90.88
- At or above
- 9.12%
Normal reference · mean 100 · SD 15. These are calculated values, not observed starp population ranks.
Where 120 sits on the IQ scale
A score of 120 is 20 points above the mean. Dividing by the standard deviation gives (120 − 100) ÷ 15 = 1.33. The normal cumulative distribution converts that standardized position into percentile 90.88.
This is above the central 85–115 interval and below two standard deviations above the mean. It indicates a higher position on this reference scale; it is not a percentage of questions answered correctly or a prediction about a particular career.
How common is a score of 120?
Approximately 9.12% of this model lies at or above 120—about 1 in 11. This is a cumulative share, not the chance of scoring exactly 120. A continuous model does not assign a positive probability to one exact value.
Compared with IQ 115, the reference percentile is 6.74 percentage points higher. Equal IQ-point gaps do not create equal percentile gaps: the middle of the bell curve contains more area than its ends.
Compare nearby scores
Compare 115 and 120 or calculate 120 on another scale. A small difference between test results is not automatically a meaningful change.
How this relates to starp
starp's current 30-question scoring map produces 120 from 26 correct answers (86.67% correct). That accuracy percentage is different from the normal-model percentile above. The scoring map was calibrated with 12,700 simulated assessments; it is not population norming.
See the scoring method and how raw scores differ from IQ estimates.
Questions about IQ 120
Is 120 a good IQ score?
120 is above the reference mean of 100. It is a higher score on that scale, but a number alone cannot establish a specific skill profile or predict success.
What percentile is an IQ of 120?
On a normal scale with mean 100 and standard deviation 15, 120 corresponds to approximately percentile 90.88. Around 9.12% of that model lies at or above it. Use an assessment's own norms for an actual reported rank.
Does an IQ of 120 mean 120% correct?
No. IQ is a scaled score. Percentage correct depends on the questions and scoring rules; percentile describes a relative position. These three quantities are not interchangeable.
Method: NIST's normal-distribution formula. Percentiles here are calculated reference values, not observed starp population ranks. About starp scoring.