What was Thomas Jefferson’s IQ?
The number, and the hoax.
Political figures attract more invented IQ numbers than any other category — this is where the documented hoaxes live.
Thomas Jefferson’s estimated IQ
- Principal author of the Declaration of Independence at 33.
- Founded the University of Virginia and designed its buildings; his library became the seed of the Library of Congress.
- Read several languages and wrote extensively on law, architecture, agriculture and natural history.
Presidential IQ figures are the single most hoax-prone corner of this subject — invented numbers reached the mainstream press in 2001 and are still repeated. Treat any precise figure for any president with suspicion, including a precise reading of this range.
- Born
- 13 April 1743, Shadwell, Virginia
- Died
- 4 July 1826, Monticello
- Field
- Law, politics, architecture
- Education
- College of William & Mary
- Known for
- Declaration of Independence; third US President
- Nationality
- American
What an IQ of 150–170 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 Thomas Jefferson was
Jefferson entered college at sixteen, qualified as a lawyer, and drafted the Declaration of Independence at thirty-three. He went on to serve as Governor of Virginia, Minister to France, the first Secretary of State, Vice President and third President.
Outside politics he designed Monticello and the University of Virginia, kept meticulous records on agriculture and weather, read several languages, and assembled a library so substantial that it became the foundation of the Library of Congress. He also enslaved more than six hundred people over his lifetime — a fact the “founding genius” framing tends to omit, and one that belongs in any honest account of the record.
The breadth of that documented output is exactly what historiometric methods respond to, and it is why his name attracts a high estimate. What the method cannot see is how much of it was capability and how much was position, wealth and forced labour.
By Elora Mercer, Celebrity Research WriterFigures checked by Leon Falkner, Data & Research AnalystReviewed by Aarav Vardhan, Editor-in-Chief · Last reviewed August 2026
Thomas Jefferson: 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.
- 1760Enters the College of William & Mary at sixteen.
- 1767Admitted to the Virginia bar.
- 1776Drafts the Declaration of Independence at thirty-three.
- 1779Elected Governor of Virginia.
- 1785Appointed Minister to France.
- 1790Becomes the first United States Secretary of State.
- 1801Inaugurated as the third President.
- 1803The Louisiana Purchase.
- 1815Sells 6,487 volumes to Congress for $23,950, rebuilding the Library of Congress after the fire of 1814.
- 1819Founds the University of Virginia and designs its campus.
- 1826Dies on 4 July, fifty years to the day after the Declaration.
Where the 160 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.
Presidential IQ figures are the most hoax-prone corner of this entire subject, and the clearest case is documented. In 2001 a fabricated table of presidential IQ scores, credited to a non-existent “Lovenstein Institute”, circulated widely. The Guardian published it in July 2001 and retracted it two days later. It resurfaced in the Spanish press in 2007 and still appears in social posts today.
That history should colour how any figure for any president is read — including a figure produced by a legitimate method. If a number is politically useful, it will be invented, and inventions in this space have proven remarkably durable.
Jefferson is among the figures historiometric work has assessed, and the documented record is genuinely extensive: legal training, architecture, an enormous library, decades of correspondence. It is a strong record. It is still not a measurement.
How we read a number →Markedly lower than Newton or Voltaire in the very same table — a useful check on the assumption that eminence and estimate move together.
Fabricated figures attributed to a non-existent body. Published by The Guardian in July 2001 and retracted within two days; resurfaced in Spain in 2007.
6,487 volumes for $23,950. Approved by the House on 26 January 1815 and signed by President Madison on 30 January 1815.
The standard scholarly edition, and the documentary base the estimate reasons from.
The sources behind our estimate
The figures that circulate for Thomas Jefferson, what we were able to confirm, and where the two diverge.
The figure that circulates most widely, frequently traced to fabricated presidential IQ tables.
No president has a published, administered IQ result. Jefferson has historiometric estimates from legitimate academic work, but his name also appears in the 2001 hoax table that The Guardian retracted. Any figure quoted for a president needs its provenance checked before it is repeated.
The 138 is a hoax figure from the fabricated 2001 table. It is listed here precisely because it is still in circulation.
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.
Thomas Jefferson — frequently asked
What was Thomas Jefferson’s IQ?
He was never tested. Figures attached to him are retrospective historiometric estimates, and the presidential IQ genre in particular has a documented history of fabrication.
What was the presidential IQ hoax?
A 2001 hoax invented scores for US presidents and credited them to a non-existent institute. The Guardian published it in July 2001 and retracted it two days later; it resurfaced in the Spanish press in 2007 and still circulates.
Are any presidential IQ scores real?
No administered, published result exists for any of them. Everything in circulation is inference or invention.
How many languages did Jefferson speak?
He read several, including Latin, Greek and French, and studied others. Contemporary accounts and his own correspondence support this; the specific counts that circulate online vary and are often inflated.
Why are presidential IQ lists so unreliable?
Because they are politically useful and easy to fabricate. The 2001 hoax is the clearest case, and its numbers still resurface in social posts today.
What happened to Jefferson’s library?
He sold roughly six and a half thousand volumes to the United States in 1815 after the Library of Congress was burned, and that collection became its foundation.
How does my IQ compare with Thomas Jefferson?
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 politics profiles, starting with John F. Kennedy.
- 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 politics profiles — same field, same method
More politics
Official White House photograph by Emily J. Higgins (2026), public domain. Background removed for the portrait above. · Official portrait by the U.S. Department of State (January 2009), public domain. Background removed for the portrait above. · Portrait by Gilbert Stuart (the Williamstown portrait, his copy of the Athenaeum portrait, in the Clark Art Institute), public domain.
An estimate is an inference.
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