What is Sherlock Holmes’ IQ?
Sherlock Holmes has no official IQ: Arthur Conan Doyle never gives one, the figure most often quoted is 190, and our character-based estimate is 180–200.
Sherlock Holmes has no official IQ: Arthur Conan Doyle never gives one. The figure most often quoted is 190, and our Sherlock Holmes IQ estimate, based on the character as written, is 180–200. The only evidence is the canon: four novels and 56 short stories from 1887 to 1927. Its best clue is Watson’s list of Holmes’s limits, which rates literature, philosophy and astronomy “Nil.”
Sherlock Holmes’ estimated IQ
- Conan Doyle writes him performing chained inference from minute physical detail, at speed, repeatedly, in four novels and 56 short stories (1887–1927).
- Watson’s list of “his limits” in A Study in Scarlet, chapter 2, rates chemistry “Profound” and sensational literature “Immense,” and gives him a good practical knowledge of British law, but rates literature, philosophy and astronomy “Nil” and politics “Feeble.”
- In the same chapter Holmes says a man’s brain is “like a little empty attic” to be stocked only with useful furniture, and, told that the earth goes round the sun, he answers, “Now that I do know it I shall do my best to forget it.”
- In The Greek Interpreter (1893) he says his brother Mycroft is his “superior in observation and deduction” but has “no ambition and no energy,” so the text itself puts a ceiling on his own rank.
A character can be written to be right every time, which no real reasoner is. Fictional estimates say something about the author’s intent, not about a mind — which is exactly why we can publish one freely.
- First appeared
- A Study in Scarlet, 1887
- Created by
- Arthur Conan Doyle
- Field
- Consulting detective
- Known for
- Deductive reasoning; 221B Baker Street
- Canon
- Four novels and 56 short stories, 1887–1927
- Author’s description
- “A calculating machine” (Memories and Adventures, 1924)
- Status
- Fictional
What an IQ of 180–200 actually means
Set the claim aside for a moment. If someone genuinely scored in this range, here is what that would represent.
Average is 100 by construction, and about two-thirds of people fall between 85 and 115. Take the test to place your own score on this scale.
| Score range | Classification | Share of people | What it indicates |
|---|---|---|---|
| 85 – 114 | Average | ~68% | The range most people fall into. |
| 115 – 129 | Above average | ~13.6% | Roughly one person in seven. |
| 130 – 144 | Gifted | ~2% | The threshold most high-IQ societies use. |
| Above 144 | Highly gifted | ~0.1% | Figures above this range are extrapolated from the curve rather than measured. |
Percentages are approximate and describe a normal distribution. The same number means different things on tests with different standard deviations.
Thirty questions gives you a measured position on this exact scale — your score, your percentile and the ability breakdown behind it.
Find out in 30 minutes →Who Sherlock Holmes is
Sherlock Holmes is a fictional consulting detective created by Arthur Conan Doyle. He first appeared in A Study in Scarlet in 1887 and became popular enough through the Strand Magazine that Conan Doyle wrote of being inclined to “weary of him” because “his character admits of no light or shade.” He killed the character in “The Final Problem” in 1893 and revived him in 1903 in “The Adventure of the Empty House.” The canon runs to four novels and 56 short stories, the last published in 1927.
The method the character is famous for, reading a life from a sleeve, a boot, a callus, was drawn from a real person. Conan Doyle studied medicine in Edinburgh under Joseph Bell, a surgeon at the Edinburgh Infirmary whose strong point, Doyle wrote, “was diagnosis, not only of disease, but of occupation and character.” When Doyle planned a detective he thought of “my old teacher Joe Bell, of his eagle face, of his curious ways, of his eerie trick of spotting details.”
He is included here for a specific reason. Fictional characters attract genuine IQ search demand, and they are the only subjects in this section where publishing an estimate misrepresents nobody at all.
By Elora Mercer, Celebrity Research WriterFigures checked by Leon Falkner, Data & Research AnalystReviewed by Aarav Vardhan, Editor-in-Chief · Last reviewed November 2026
Sherlock Holmes: the documented record
The estimate above rests on this record. Every entry here is a matter of public fact, which is more than can be said for the number itself.
- 1887First appears in A Study in Scarlet, published in Beeton’s Christmas Annual.
- 1890The Sign of the Four.
- 1891The Strand Magazine stories begin, illustrated by Sidney Paget.
- 1892The Adventures of Sherlock Holmes collected.
- 1893Conan Doyle kills the character in “The Final Problem”.
- 1893Mycroft Holmes is introduced in “The Greek Interpreter.”
- 1901The Hound of the Baskervilles, set before Holmes’s death.
- 1903Holmes returns in “The Adventure of the Empty House”.
- 1927The final collection, The Case-Book of Sherlock Holmes.
Where the 190 figure came from
Following a claim back to its first appearance is the part almost nobody does — and it is what most people are actually asking.
Conan Doyle never gives Holmes an IQ, and could not have — the stories begin in 1887, before intelligence testing existed in any recognisable form. Every figure attached to the character was invented by someone else, long afterwards.
What does the text say about Holmes’s mind? In A Study in Scarlet (chapter 2, “The Science of Deduction”), Watson jots down a list headed “Sherlock Holmes—his limits.” Literature, philosophy and astronomy are “Nil,” politics “Feeble,” botany “Variable” and geology “Practical, but limited.”
The same list rates chemistry “Profound,” anatomy “Accurate, but unsystematic” and sensational literature “Immense,” and gives him a good practical knowledge of British law. The character is written as a specialist, not a universal genius. That list is why this page puts him at 180–200, not higher; you can read it in the text at Project Gutenberg.
He is also written to be right. Real reasoning under uncertainty produces wrong answers regularly; Holmes almost never does. That is a property of authorship, not of intellect, and it is the main reason a figure derived from his performance would mean nothing even if we published one confidently.
Who is smarter, Holmes or Mycroft? The stories answer directly. In The Greek Interpreter Holmes says Mycroft is “my superior in observation and deduction,” but has “no ambition and no energy.” This site follows the text: Mycroft Holmes is 185–205 and Sherlock 180–200, with Professor Moriarty at 175–195. The author, Arthur Conan Doyle, is 130–145 on the evidence of a medical degree and a writing career. For the quoted 190, see what an IQ of 190 means.
Which real people echo him? Benedict Cumberbatch (125–140) has played Holmes on screen, and Hugh Laurie (120–140) played Gregory House (150–170), a doctor whose small-detail reading ties him to Holmes. Actors are not characters, and none of them has a published score. For other invented minds on this site, see our fictional characters category, and take the IQ Metrics test to see where your own score falls.
How we read a number →Watson’s list headed “Sherlock Holmes—his limits” (literature, philosophy, astronomy “Nil”; politics “Feeble”; chemistry “Profound”; sensational literature “Immense”), Holmes’s ignorance of the Copernican theory and his “little empty attic” remark, all read in the Gutenberg text.
Holmes on Mycroft: “he was my superior in observation and deduction. If the art of the detective began and ended in reasoning from an armchair, my brother would be the greatest criminal agent that ever lived. But he has no ambition and no energy.”
Doyle’s own account: “one Joseph Bell, surgeon at the Edinburgh Infirmary,” as the model for the method, and his description of Holmes as “a calculating machine” whose character “admits of no light or shade.”
Holmes appeared in a total of 56 short stories, the last published in 1927, and four novels, and was killed off in 1893.
Ranges used for comparison: Mycroft 185–205, Moriarty 175–195, Conan Doyle 130–145, Cumberbatch 125–140, Laurie 120–140, House 150–170.
No story or novel gives Holmes an IQ, and the first intelligence scale appeared in 1905, 18 years after his first story.
The sources behind our estimate
The figures that circulate for Sherlock Holmes, what we were able to confirm, and where the two diverge.
The figure most often assigned to the character across fan discussion and IQ listicles.
Conan Doyle never assigns Holmes an IQ, and the first intelligence scale, the Binet-Simon test of 1905, appeared 18 years after the first story. Every figure was invented afterwards. Ours describes how the character is written, a specialist drawn to be right every time, not a person. Doyle’s own description in Memories and Adventures (1924) is that Holmes “is a calculating machine.”
Unusually, the spread here does no harm: there is no one being misrepresented, which is exactly why this is the one category where a confident-looking number is harmless.
Want a number that does hold up? Every figure on this page is somebody’s claim. Take the 30-question test and get a percentile you can check rather than a figure you have to trust.
Sherlock Holmes — frequently asked
What is Sherlock Holmes’s IQ?
Sherlock Holmes has no official IQ: Arthur Conan Doyle never gives one, the figure most often quoted is 190, and our character-based estimate is 180–200. It describes how the character is written, not a person.
What is Sherlock Holmes’s IQ level (QI de Sherlock Holmes)?
There is no stated level. The “IQ level” people search for in English and the “QI de Sherlock Holmes” in French both lead to fan figures around 190 that no story supports. The text gives a list of strengths and gaps, not a score.
Is Sherlock Holmes’s IQ higher than Mycroft’s?
No, by the text. In The Greek Interpreter Holmes says Mycroft is his “superior in observation and deduction” but has “no ambition and no energy.” This site puts Mycroft at 185–205 and Sherlock at 180–200.
What does the book say about Holmes’s knowledge?
In A Study in Scarlet, Watson’s list rates Holmes’s knowledge of literature, philosophy and astronomy “Nil,” politics “Feeble,” chemistry “Profound” and sensational literature “Immense.” He did not know that the earth goes round the sun and says he will try to forget it.
Was Holmes based on a real person?
Conan Doyle credited Joseph Bell, a surgeon at the Edinburgh Infirmary he studied under, whose strong point he wrote was diagnosis “not only of disease, but of occupation and character.” In his memoir he says he thought of Bell when he planned the detective.
Is Sherlock Holmes’s reasoning realistic?
Mostly not. He performs abduction, inference to the best explanation, presented as deduction, and the stories are written so his first guess is almost always right. Doyle called him “a calculating machine.” Real reasoning under uncertainty is not like that.
Why include fictional characters at all?
Because people search for them, and because it is the only part of this subject where estimating a number harms nobody.
How many Sherlock Holmes stories are there?
Four novels and 56 short stories by Arthur Conan Doyle, published from 1887 to 1927. Holmes was killed in “The Final Problem” in 1893 and returned in “The Adventure of the Empty House” in 1903.
How does my IQ compare with Sherlock Holmes?
You can find out in about fifteen minutes. The IQ Metrics assessment is 30 questions, scored on the same 100-mean scale used throughout this page, so your result and the estimate above are at least expressed in the same units — one measured, one inferred. Once you have a number, the leaderboard shows where it would sit, and how we score and norm it explains the benchmarking.
Where does this estimate come from?
From the documented record rather than a test — the method is named above and set out in full under how we read a number. Compare it against the other fictional profiles, starting with Professor Moriarty.
- Take the 30-question IQ test — get a measured score and percentile of your own
- Average IQ by country — how the scale behaves across populations
- How IQ Metrics scores its assessment — the method behind our own number
- More on how IQ testing works — reliability, error and what a score can and cannot say
- More fictional profiles — same field, same method
More fictional
Photograph of a cosplayer as Shikamaru Nara by Narukyubi (2009), CC BY-SA 3.0. Cropped from the original. The character is the creation of Masashi Kishimoto. · Photograph of a cosplayer as Kurisu Makise by Carter McKendry, CC BY 2.0. Background removed for the portrait above. The character is the creation of 5pb. and Nitroplus. · Photograph of a cosplayer as Itachi Uchiha by BrokenSphere (2010), CC BY-SA 3.0. Cropped from a two-person photograph; background removed for the portrait above. The character is the creation of Masashi Kishimoto.
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