How rare is an IQ of 125?
An IQ of 125 is at the High level. Under a normal model with mean 100 and standard deviation 15, IQ 125 or above has the following estimated frequency.
Deviation score
66.7
Top
4.78%
Rarity
1 in 21
z-score
1.67
On the normal-distribution model with a mean of 100 and a standard deviation of 15, an IQ of 125 corresponds to roughly the top 4.78% (about 1 in 21 people), a deviation score of 66.7, and a standard score of z = 1.67. 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 = (125 − 100) ÷ 15 ≈ 1.67
- Share scoring 125 or above
- [1 − Φ((125 − 100) ÷ 15)] × 100 ≈ 4.78%
- Deviation score
- 50 + (125 − 100) ÷ 15 × 10 ≈ 66.7
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 120 / 125 / 130 compared
| IQ | Top % | Rarity |
|---|---|---|
| IQ120 | 9.12% | 1 in 11 |
| IQ125this page | 4.78% | 1 in 21 |
| IQ130 | 2.28% | 1 in 44 |
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 125
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 125 is 25 points at or above the mean; the share scoring 125 or above is about 4.78%.
- •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 125 or above corresponds to the top 4.78%. 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 125?
- An IQ of 125 corresponds to roughly the top 4.78%, or about 1 in 21 people scoring 125 or above, assuming a normal model with mean 100 and SD 15.
- Is an IQ of 125 high? Is it impressive?
- It is at the High level, placing it in roughly the top 4.78%. 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 125?
- 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 125 or above corresponds to the top 4.78%. Admission cutoffs depend on the accepted test; a BrainRank estimate or certificate cannot establish eligibility.
- What is the deviation score for an IQ of 125?
- Converting IQ (mean 100, SD 15) to a deviation score gives about 66.7.
Common questions in the IQ 120–129 band
- Is an IQ of 125 enough to join 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 125 or above corresponds to the top 4.78%. Admission cutoffs depend on the accepted test; a BrainRank estimate or certificate cannot establish eligibility.
- Is an IQ in the 120s considered "gifted"?
- Most definitions of gifted start around IQ 130 (top ~2%). The 120s — roughly the top 9.12% to 2.66% — are usually labeled "superior" or "high," a level where complex reasoning tasks tend to feel comfortable, though it falls just below common gifted cutoffs.
- Does an IQ of 125 determine which careers suit me?
- No. Group averages differ across professions, but the spread within every profession is large. An IQ of 125 is compatible with essentially any career; interest, training, and practical skills are far stronger predictors of success in a specific field.
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.