What does an IQ of 159 mean?
At the upper end on the reference scale, at approximately percentile 99.9958.
- IQ score
- 159
- Percentile
- 99.9958
- At or above
- 0.0042%
Normal reference · mean 100 · SD 15. These are calculated values, not observed starp population ranks.
Where 159 sits on the IQ scale
A score of 159 is 59 points above the mean. Dividing by the standard deviation gives (159 − 100) ÷ 15 = 3.93. The normal cumulative distribution converts that standardized position into percentile 99.9958.
This is at least three standard deviations above the mean. The modeled upper tail is very small, so rounding and differences between scoring scales matter more. A precise-looking reference percentile does not make an extreme result from an unvalidated test precise.
How common is a score of 159?
Approximately 0.0042% of this model lies at or above 159—about 1 in 23,873. This is a cumulative share, not the chance of scoring exactly 159. A continuous model does not assign a positive probability to one exact value.
Compared with IQ 145, the reference percentile is 0.13 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 154 and 159 or calculate 159 on another scale. A small difference between test results is not automatically a meaningful change.
How this relates to starp
The current starp score range ends at 144. A score of 159 is covered here as a general scale reference, but it is not a result the current starp test can produce. Its normal-model percentile should not be presented as a starp ranking.
See the scoring method and how raw scores differ from IQ estimates.
Questions about IQ 159
Is 159 a good IQ score?
159 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 159?
On a normal scale with mean 100 and standard deviation 15, 159 corresponds to approximately percentile 99.9958. Around 0.0042% of that model lies at or above it. Use an assessment's own norms for an actual reported rank.
Does an IQ of 159 mean 159% 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.