IQ 158

In a town of 100,000 people, the bell curve expects only about 6 at 158 or higher. That rarity, about 1 in 18,100, is what puts 158 in the highly gifted range.

People this rare can find it takes effort to meet intellectual peers. University departments, clubs and communities built around hard problems help.

A very high score is not a forecast. Eminence depends on years of work, opportunity, collaborators and luck as much as on ability.

People who score around 158, and the teachers who work with them, often describe some of the following. Treat it as a set of possibilities, not a profile:

• Complex ideas can click after one explanation, which makes slow-paced teaching feel frustrating.
• It can be hard to judge what is obvious to other people, so explaining clearly takes practice.
• In children, reasoning can run years ahead of age while emotional and physical development stay on schedule. Educators call this asynchrony.

To check a score of 158, a test would need plenty of people at that level in its norm group. With a typical 2,200-person sample, it would expect less than one. That is why scores this high carry more uncertainty.

Ceiling effects set in when a test runs out of hard questions. Strong test-takers then bunch at the top and the score stops separating them.

Short online tests, including ours, are best at telling you roughly where you are. Treat a 158 from one as "well above 140" rather than an exact figure.

On a bell curve with a mean of 100 and a standard deviation of 15, about 0.0055% of people score 158 or higher. Applied to whole populations:

Compare the neighbours: 153 or higher is about 1 in 4,873, 158 or higher is 1 in 18,100, and 163 or higher is 1 in 74,900. Each point up here adds roughly 32% to the rarity.

What your 158 could really be. Even a good supervised test has a margin of error of roughly 5 points either side. A true score anywhere from 153 to 163 would be consistent with a 158, which spans the 99.98th to the 99.999th percentile. Short online tests have wider margins.

Which scale was it on? Score reports do not always say. On the common SD 15 scale your 158 stands as it is. If the report used SD 16 it equals about 154, and if it used SD 24 about 136. The percentile follows the converted number.

Scientists, composers and philosophers often receive estimates in this range. These sit near 158. None of these are test scores. They are estimates from biographical evidence, and each profile explains its basis.

How 158 stacks up against the scores just around it and the round numbers people usually ask about. Each score links to its own page.

People with an IQ of 158 typically score about 1600 on the SAT and about 36 on the ACT composite. Scores vary a lot from person to person, so the range shows where about four in five land.