IQ 186

186 is 5.73 standard deviations above the mean. On a bell curve that works out to about 1 in 200 million people, which would mean fewer than one (0.34 expected) in the UK and about 40 worldwide. The bell curve is a model, though, and at this height it is doing most of the work.

Major individually administered adult tests typically report full-scale scores up to about 160. A reported number above that usually comes from extended norms, a different scale or extrapolation.

Real populations may not follow the bell curve perfectly in the far tails, so rarity figures this extreme are illustrations, not head counts.

A 186 almost never comes from a modern, supervised adult test. It usually comes from somewhere like this:

• Ratio IQ. Early childhood tests divided mental age by real age. A 6-year-old solving puzzles like a typical 11.2-year-old got a ratio IQ of 186. Modern deviation IQs do not work this way.
• Unnormed online quizzes. A test with no norm data can print any number. Very high outputs usually say more about the scoring than the person.
• Repetition without a source. Numbers attached to celebrities are often copied from site to site with no test report behind them.

42 of the historical profiles on this site carry an estimate of 160 or more, and 3 reach 186 or higher. Isaac Newton and Leonardo da Vinci are the classic examples. Their numbers are retrospective judgements based on their work, not test scores.

Estimates this high mostly reflect how extraordinary the achievement was. That is a different thing from how someone would perform on a timed reasoning test.

On a bell curve with a mean of 100 and a standard deviation of 15, about 0.00000049% of people score 186 or higher. Applied to whole populations:

An IQ of 186 or higher is 6.8 times rarer than 181 or higher, and 191 or higher is 7.5 times rarer again. At this point on the curve, each extra point makes a score about 48% rarer.

What your 186 could really be. No test is precise this far out. Even a 5-point error band, from 181 to 191, spans a rarity gap of about 51 times, so the exact number matters much less than "very far above average".

Which scale was it on? A 186 reported on an SD 16 scale converts to about 181 on the usual SD 15 scale, and one from an SD 24 scale (seen in some Cattell-style results) to about 154. Check which scale your score report used.

Estimates this high are reserved for a small group of scientists, artists and thinkers. These sit near 186. Every figure below is a retrospective estimate, not a measured score. Open a profile to see the evidence and how confident anyone can be.

The scores one and five points either side of 186, plus the round numbers from 100 to 150, side by side. Tap any score for its full page.