What Percentage Has an IQ of 150? Top 0.04%, About 1 in 2,330

An IQ of 150 puts you in roughly the top 0.04%, about 1 in 2,330 people. On a normal distribution with a mean of 100 and a standard deviation of 15 (SD 15), it sits +3.33 standard deviations above the mean, which converts to a deviation score of 83.3. This article shows where those numbers come from and how the score compares with its neighbors.

The core numbers for IQ 150 (mean 100, SD 15)

Computed on the SD-15 normal distribution model, an IQ of 150 gives these values:

• Standard score (z): +3.33
• Percentile: top 0.04% or so
• Rarity: about 1 in 2,330 people
• Deviation score: 83.3

All four follow arithmetically from the definition of a normal distribution with a mean of 100 and a standard deviation of 15 — no source beyond the statistical model is required. The IQ reference table lists every score computed the same way.

Line it up against IQ 140 and IQ 160

At the high end, ten points changes rarity by an order of magnitude. On the SD-15 model:

• IQ 140: top 0.38% or so (about 1 in 261)
• IQ 150: top 0.04% or so (about 1 in 2,330)
• IQ 160: top 0.003% or so (about 1 in 31,560)

So the gap between IQ 140 and IQ 150 is roughly 9x in rarity, and the gap between IQ 150 and IQ 160 is roughly 14x. What was '1 in 50' around IQ 130 becomes 'perhaps one person in an entire school' at 150. Reading this alongside the percentage for IQ 140 and the percentage for IQ 130 makes the non-linear jump obvious.

'IQ 150' means different things on different rulers

One caveat matters here: IQ scales exist with different standard deviations. SD 15 is standard on the major tests used in Japan, Europe, and North America, but some tests and high-IQ societies use SD 24. On an SD-24 scale, an IQ of 150 is +2.08 standard deviations, roughly the top 2%, which converts to about IQ 131 on SD 15.

That is the same number, 150, meaning either 1 in 2,330 or 1 in 50 — a difference of more than 40x in rarity. Whenever you see 'IQ 150' quoted online, check which standard deviation the scale uses. Every figure on this site is standardized on SD 15 (see our methodology).

Top 0.04% is stricter than high-IQ society thresholds

Mensa, the best-known international high-IQ society, admits the top 2% (equivalent to IQ 130 on SD 15). The top 0.04% represented by IQ 150 is far stricter than that — it is a small slice even among Mensa members. The application process is covered in how to join Mensa.

Measurement error also matters more in this band. Because a margin of about ±5 points is expected even on standardized tests, IQ 145 and IQ 155 can be statistically hard to tell apart. Treat no single sitting as a definitive value.

Measure your own position on the same ruler

A number like 150 only becomes comparable when it is measured on the same scale. BrainRank's free IQ test takes about 10 minutes across 20 questions and uses item response theory (IRT) scoring to produce an estimated IQ, deviation score, and percentile on the mean-100, SD-15 scale. Because every figure uses the same normal-distribution model as this article, you can compare your result directly against the IQ distribution data.