An IQ score of 138 falls into the Gifted range on the standard intelligence scale (mean = 100, standard deviation = 15). This score is in the top 2–5% of the population — this is roughly the Mensa threshold range (IQ 130 on most scales).
What an IQ of 138 means
An IQ of 138 is at about the 99.4th percentile, roughly one in 177 people. It is in the gifted range and well above the 1% line. Precision is worth thinking about here: most tests are normed on a few thousand people, so only a handful of people in the norm sample score near 138, and the exact percentile at this height depends heavily on statistical assumptions. A good way to read this score is in the top half-percent or so, give or take, rather than as an exact rank.
Where does an IQ of 138 rank?
On a standardized IQ test, a score of 138 places you higher than approximately 99.4% of the population. Intelligence scores follow a normal distribution — most people cluster near 100, and scores taper off sharply toward both extremes.
| Metric | Value |
|---|---|
| IQ score | 138 |
| Classification | Gifted |
| Percentile | 99.4% |
| Rarity (out of 1,000) | ~6 in 1,000 score this high or higher |
| Standard deviations from mean | 2.53 |
IQ 138 in numbers
- Roughly 1 in 177 people score 138 or higher.
- In a room of 100 randomly chosen adults, about 1 would score 138 or higher.
- That is 8 points above 130, the level most high-IQ societies use as their entry line.
- Another 2 points would move this score into the Highly Gifted band, which starts at 140.
- Even on professionally administered tests a single result has a margin of error of about five points either way, so a measured 138 is best read as somewhere between 133 and 143.
On our free IQ test
Of the 3,834 people who completed our free IQ test between April and October 2026, 35 scored exactly 138 and 3.1% scored higher. People who choose to take an online IQ test are not a random sample of the population (our average is 114.5), so this shows where a score sits among other test-takers, not among everyone. More in our 2026 data study.
Which IQ tests produce a score of 138?
A score of 138 can be produced by any standardized intelligence test that uses the mean = 100, SD = 15 scale. The most widely used tests include:
- Wechsler Adult Intelligence Scale (WAIS) — clinical gold standard for adults.
- Stanford-Binet Intelligence Scales — oldest continuously-used intelligence test.
- Mensa admissions test — used by the Mensa society for membership selection.
- Cattell-Horn-Carroll (CHC) tests — most theoretically grounded modern framework.
- Our free IQ test — instant online estimate with the same scaling.
How to interpret an IQ score of 138
Scores of 130 and above are in the gifted range, which is commonly the threshold for Mensa International membership (on tests with SD = 15). People at this level often excel at abstract reasoning, pattern detection, and rapid learning in new domains. Note that Mensa uses 132 on the Cattell scale (SD = 24), so the threshold depends on which test was taken.
IQ 138 in Context
| IQ Range | Classification | Population % |
|---|---|---|
| Below 70 | Extremely Low | ~2.2% |
| 70–79 | Borderline | ~6.7% |
| 80–89 | Low Average | ~16.1% |
| 90–109 | Average | ~50% |
| 110–119 | High Average | ~16.1% |
| 120–129 | Superior | ~6.7% |
| 130+ | Gifted / Very Superior | ~2.2% |
Factors That Influence Your Score
Your IQ score reflects a combination of genetic potential and environmental influences including education, nutrition, health, and the testing conditions themselves. Factors like fatigue, anxiety, unfamiliarity with the test format, and even the time of day can all affect performance. A single test score should be viewed as an estimate, and scores can vary by several points between testing sessions.
Nearby scores
Compare the major IQ tests
Which test produces the most accurate score depends on what you're trying to measure. These head-to-head comparisons break down the differences:
- WAIS vs Stanford-Binet — the two clinical heavyweights compared.
- Mensa vs WAIS — entry-test speed vs full clinical assessment.
- Stanford-Binet vs Mensa — which one actually gets you into Mensa.
- CHC vs Wechsler — modern cognitive framework vs the classic.
- Raven vs Cattell — non-verbal alternatives for cross-cultural testing.
Further reading
- What is a good IQ score?
- What does your IQ score mean?
- Average IQ by age
- Mensa requirements
- IQ test types compared
Want to find out your IQ score?
Take a free, comprehensive cognitive assessment modeled on clinical IQ tests.
Take the Free IQ TestFrequently asked questions
Is IQ 138 considered good?
Yes — an IQ of 138 is well above average and falls in the gifted range. It's higher than approximately 99% of the population and typically exceeds the Mensa International admission threshold (130 on SD-15 tests).
Can an IQ of 138 change over time?
IQ scores are relatively stable in adulthood but can shift modestly with education, engagement, sleep, and health. Short-term factors like stress and fatigue can move a single test result by 5–10 points in either direction — which is why we recommend comparing results across multiple sessions rather than reading too much into any single score.
What percentile is IQ 138?
An IQ of 138 corresponds to the 99.4th percentile on the standard bell curve — meaning it is higher than about 99 out of every 100 people.