IQ 99
What does an IQ of 99 mean?
99 sits in the middle of the Average band. Here is where that puts you on the curve, how common it is, and what the score does and does not predict.
Short answer
An IQ of 99 is a little below average. It is higher than about 47.3% of people, which puts it at the 47.3 percentile. About 1 in 2 people score 99 or lower, and the WAIS-IV labels it Average (90 to 109). It is 0.07 standard deviations below the mean of 100.
Specimen · IQ 99
99IQ
- Classification
- Average
- Percentile
- 47.3
- Rarity
- 1 in 2
- z-score
- −0.07
Curious where you would land? IQ Octopus estimates your IQ from 25 visual puzzles in about 12 minutes.
| Percentile | 47.3 |
| Share scoring 99 or lower | 47.3% (about 1 in 2) |
| Out of 1,000 people | about 473 at or below |
| Standard deviations from the mean (z) | -0.07 |
| WAIS-IV classification | Average (90 to 109) |
| Same percentile, SD 16 scale | 99 |
| Same percentile, SD 24 scale | 98 |
What an IQ of 99 means on the scale
Modern IQ tests report a deviation IQ: scores are standardized so the mean is 100 and the standard deviation is 15 within each age group (Wikipedia: Intelligence quotient). On that scale 99 is 0.07 standard deviations below the mean. It sits inside the 85 to 115 range, where about 68% of people score. (the 68-95-99.7 rule)
In a room of 30 people your age, about 14 would be expected to score 99 or lower. Put another way, about 53 out of every 100 people score above 99.
The Average band: 90 to 109
Average covers 90 to 109 on the WAIS-IV scale (Wikipedia: IQ classification) and is the largest band by far: about 49% of people score in it. Half of everyone tested lands within this 20-point stretch.
The band is centered on 100, the mean of the scale by construction (Wikipedia: Intelligence quotient). 99 is on the lower side of the middle: 1 point below the mean, and 10 above the top of the Low Average band (89). Within this band, differences of a few points are smaller than the error of any test, so 95 and 105 are best read as the same kind of result.
Where 99 sits inside the band
99 is 9 points above the floor of the Average band (90) and 10 points below its ceiling (109). Of the people who score in this band, about 44% score below 99.
Clinical IQ scores carry measurement error of around plus or minus 5 points at 95% (Wechsler, 2008). A measured 99 is consistent with a true score anywhere from 94 to 104, which is the 34.5 to 60.5 percentile. That whole range stays inside the Average band, so the label is the most stable part of the result. A short online test has a wider range than a clinical one, so read any single number as the middle of a span.
What an IQ of 99 does and does not predict
An average score means your reasoning on these puzzles matched the typical person your age. It leaves plenty of room for strengths the test does not measure, from knowledge and skills to persistence.
Across large groups, the links are real. General intelligence at age 11 correlated 0.81 with exam results at 16 in about 70,000 English children (Deary, Strand, Smith & Fernandes, 2007), a review of 85 years of workplace research put the link with job performance at 0.51 (Schmidt & Hunter, 1998), and a 2007 meta-analysis found correlations of about 0.56 with education and 0.23 with income (Strenze, 2007). Those describe tendencies across many people. None of them let anyone predict an individual life from one number. The guide to what IQ predicts explains what a correlation of that size means.
Same score, different tests
Older Stanford-Binet forms used a standard deviation of 16, and the Cattell Culture Fair III scale uses 24 (Wikipedia: IQ classification). The same percentile as 99 on a standard-deviation-15 test reads as about 99 on the first and 98 on the second, so check which scale a number is on before comparing scores from different tests.
Nearby scores
| IQ | Percentile | Rarity | Classification |
|---|---|---|---|
| IQ 85 | 15.9 | 1 in 6 | Low Average |
| IQ 90 | 25.2 | 1 in 4 | Average |
| IQ 95 | 36.9 | 1 in 3 | Average |
| IQ 96 | 39.5 | 1 in 3 | Average |
| IQ 97 | 42.1 | 1 in 2 | Average |
| IQ 98 | 44.7 | 1 in 2 | Average |
| IQ 100 | 50 | 1 in 2 | Average |
| IQ 101 | 52.7 | 1 in 2 | Average |
| IQ 102 | 55.3 | 1 in 2 | Average |
| IQ 105 | 63.1 | 1 in 3 | Average |
| IQ 110 | 74.8 | 1 in 4 | High Average |
IQ 98 · IQ 100 · every score on the IQ chart · IQ percentile calculator · the seven classification bands
Sources
- Intelligence quotient. Wikipedia. en.wikipedia.org/wiki/Intelligence_quotient
- IQ classification. Wikipedia. en.wikipedia.org/wiki/IQ_classification
- 68-95-99.7 rule. Wikipedia. en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule
- Wechsler, D. (2008). WAIS-IV Technical and Interpretive Manual. Pearson.
- Deary, I. J., Strand, S., Smith, P., & Fernandes, C. (2007). Intelligence, 35(1), 13-21. doi.org/10.1016/j.intell.2006.02.001
- Schmidt, F. L., & Hunter, J. E. (1998). Psychological Bulletin, 124(2), 262-274. doi.org/10.1037/0033-2909.124.2.262
- Strenze, T. (2007). Intelligence, 35(5), 401-426. doi.org/10.1016/j.intell.2006.09.004