How rare is an IQ of 143?
An IQ of 143 is at the Very high level. Under a normal model with mean 100 and standard deviation 15, IQ 143 or above has the following estimated frequency.
Deviation score
78.7
Top
0.21%
Rarity
1 in 482
z-score
2.87
On the normal-distribution model with a mean of 100 and a standard deviation of 15, an IQ of 143 corresponds to roughly the top 0.21% (about 1 in 482 people), a deviation score of 78.7, and a standard score of z = 2.87. All four values are computed from that model rather than aggregated from test-taker data; the calculation is documented on our methodology page.
Position in the IQ distribution (mean 100, SD 15)
How the percentages are calculated
We assume a normal distribution with mean 100 and SD 15. Φ is the standard normal cumulative distribution function. Values are rounded for display.
- Standard score
- z = (143 − 100) ÷ 15 ≈ 2.87
- Share scoring 143 or above
- [1 − Φ((143 − 100) ÷ 15)] × 100 ≈ 0.21%
- Deviation score
- 50 + (143 − 100) ÷ 15 × 10 ≈ 78.7
NIST: Normal Distribution documents the distribution and its cumulative function. The mean-100, SD-15 assumption is the model used on this page, not evidence that an online test is standardized.
These frequencies describe scores at or above the stated IQ, not the number with exactly that score. Confidence intervals depend on the test and its reliability; BrainRank has not established a validated ±5-point interval.
Does 5 points matter? IQ 138 / 143 / 148 compared
| IQ | Top % | Rarity |
|---|---|---|
| IQ138 | 0.56% | 1 in 177 |
| IQ143this page | 0.21% | 1 in 482 |
| IQ148 | 0.07% | 1 in 1,455 |
This table compares theoretical population shares. It does not establish whether a five-point difference between two test results is meaningful; that depends on the test and its reliability.
How to interpret an IQ of 143
Use the number to understand a position on a scale, then check what the particular test measures.
- •On the mean-100, SD-15 model, IQ 143 is 43 points at or above the mean; the share scoring 143 or above is about 0.21%.
- •A single IQ number does not identify which tasks you find easy. Read it alongside the test's scope and your scores in each area.
- •Compare scores only after checking the test, reference group, and standard deviation. A BrainRank estimate is not interchangeable with a standardized assessment.
Relationship to Mensa
Mensa requires a score in the top 2% on an approved, properly administered and supervised intelligence test. Under the mean-100, SD-15 normal model, IQ 143 or above corresponds to the top 0.21%. Admission cutoffs depend on the accepted test; a BrainRank estimate or certificate cannot establish eligibility.
Source: Mensa International — IQ Test FAQs
Note: Most celebrity IQ figures seen online are estimates from unreliable sources. This page does not publish individual IQ values that cannot be verified.
Frequently asked questions
- What percentile is an IQ of 143?
- An IQ of 143 corresponds to roughly the top 0.21%, or about 1 in 482 people scoring 143 or above, assuming a normal model with mean 100 and SD 15.
- Is an IQ of 143 high? Is it impressive?
- It is at the Very high level, placing it in roughly the top 0.21%. That said, IQ measures only a small part of thinking and does not determine a person's worth or success.
- Can you join Mensa with an IQ of 143?
- Mensa requires a score in the top 2% on an approved, properly administered and supervised intelligence test. Under the mean-100, SD-15 normal model, IQ 143 or above corresponds to the top 0.21%. Admission cutoffs depend on the accepted test; a BrainRank estimate or certificate cannot establish eligibility.
- What is the deviation score for an IQ of 143?
- Converting IQ (mean 100, SD 15) to a deviation score gives about 78.7.
Common questions in the IQ 130–144 band
- Can I join Mensa with an IQ of 143?
- Mensa requires a score in the top 2% on an approved, properly administered and supervised intelligence test. Under the mean-100, SD-15 normal model, IQ 143 or above corresponds to the top 0.21%. Admission cutoffs depend on the accepted test; a BrainRank estimate or certificate cannot establish eligibility.
- Does an IQ of 143 mean I am gifted?
- An IQ of 143 falls in the range (130+) that many frameworks use as the gifted threshold — about 1 in 482 people. Formal identification, however, usually looks at more than one test score, and giftedness describes a pattern of abilities, not a guarantee of achievement.
- How rare is an IQ of 143 really?
- Under the standard model (mean 100, SD 15), an IQ of 143 is in roughly the top 0.21% — about 1 in 482 people. In a group of 1,000 people you would expect only about 2 at this level or higher.
Age and testing conditions
- •IQ is a deviation score relative to people of the same age: a score compares you with your own age group, so children's and adults' scores are not on the same footing.
- •Results from informal online tests, including the test on this site, are estimates. For medical or educational decisions, use a standardized test administered by a qualified professional.
- •Sleep deprivation, fatigue, and practice effects all move measured scores. Read any single result, high or low, with that in mind.