What is Richard Feynman's IQ?
Richard Feynman's IQ was 125, according to a school test recorded in James Gleick's biography — a score Gleick calls "merely respectable". Feynman won a Nobel Prize in physics. He also thought the whole business was funny, and declined to join Mensa.
A quick, honest note. Richard Feynman has a figure attributed to a named source, but it does not come from a controlled, modern test. Treat it as a report, not a measurement.
Where does the 125 number come from?
If you take one number away from this collection, take this one.
Feynman reformulated quantum mechanics, won a Nobel Prize, cracked the Challenger disaster on live television, and is on most physicists' short list of the most creative minds of the twentieth century. His measured IQ was 125 — a good score, around the 95th percentile, and thoroughly ordinary among physics graduate students.
The caveats are real: it was a single school test, probably with a low ceiling, taken decades ago, and it plainly failed to measure the mathematical ability of a boy who had taught himself calculus by fifteen. A test with a ceiling cannot measure what is above the ceiling.
But the lesson survives the caveats. A reasoning score is a narrow measurement taken on one afternoon. It does not capture obsessive curiosity, or the willingness to sit with a problem for years, or the knack for seeing a question from an angle nobody else tried. Feynman had those in quantities no test measures.
How rare would a 125 IQ be?
If the 125 figure were literally true, it would be extraordinarily rare — rarer than1 in 21 people. That alone is a good reason to treat any confident-sounding celebrity IQ number with a raised eyebrow.
Common enough to meet: in a room of a hundred people, expect about 5 at 125 or higher.
What a score like this would mean
A 125 would sit in the superior range — about one person in 21. Above most of the room, but not out of it.
Stop reading estimates about strangers. Sixteen questions and about ten minutes gets you a number that is actually yours.
Frequently asked questions
What was Richard Feynman's IQ?
A reported 125, from a high-school test recorded by his biographer James Gleick.
How can a Nobel physicist have an IQ of 125?
Because a school test with a ceiling measures a narrow slice of ability on a single day. It captured neither his mathematical depth nor the persistence and creativity his work depended on.
Did Feynman join Mensa?
No. He is widely reported to have declined, and treated his score as a joke rather than a credential.