How many people speak an invented language such as Esperanto, Klingon or Na’vi: a few thousand, a few hundred thousand or a few million?
For Esperanto, at least hundreds of thousands, but nobody has an exact count, and the main estimates measure different things. The Universal Esperanto Association (UEA) puts the number of people with some knowledge of Esperanto “in the hundreds of thousands and possibly millions,” based on textbooks sold and the membership of local societies. Separately, a 2015 paper by Amri Wandel in the journal INDECS estimates about two million Esperanto users within the internet community alone, modeled from Facebook users who say they speak it. For Klingon and Na’vi, we found no published speaker count at all.
Esperanto: a language with a birth year
Esperanto is a rare language with a known start date. Its basis was published in Warsaw in 1887 by Lejzer Ludwik Zamenhof, UEA says, as an extra second language for everyone rather than a replacement for anyone’s first. It began with about 1,000 roots; Esperanto dictionaries now often hold 15,000 to 20,000, UEA says. UEA has member associations in 70 countries and individual members in 120. According to UEA, UNESCO’s General Conference recognised in 1954 that Esperanto’s achievements match UNESCO’s aims, and in 1985 called on member states to promote teaching it in schools.
Why the estimates do not add up
UEA’s range and Wandel’s figure count different things, so we print them side by side, not as one range. UEA’s covers anyone with some knowledge of the language, and its page gives no year. Wandel’s covers internet users only and is modeled from Facebook profiles, in a paper the journal received in April 2014. Neither is a count, and neither checks the other.
Native speakers, people raised with Esperanto at home, are a much smaller group. UEA says there are as many as a thousand.
One census gives an actual count, for one country. Hungary’s 2011 census recorded 8,397 people who said they speak Esperanto, up from 2,083 in 1990 and 4,575 in 2001, its statistics office reports. That is about four times the 1990 figure (our arithmetic). These are self-reported answers from residents of Hungary only, and they cannot be scaled up to a world total.
How long a language takes to learn
The US State Department’s Foreign Service Institute publishes how long its students usually need to reach a score of 3 in speaking and listening on the government’s Interagency Language Roundtable scale. A typical week is 23 hours in class and 17 hours of self study.
- Languages close to English, such as French, Spanish and Italian: 24 to 30 weeks, or 552 to 690 class hours.
- German, Indonesian and Swahili, among others: about 36 weeks, or 828 class hours.
- “Hard languages” such as Russian, Hungarian and Polish: about 44 weeks, or 1,012 class hours.
- Arabic, Mandarin, Cantonese, Japanese and Korean: 88 weeks, or 2,200 class hours.
The hardest group takes about 3 to 4 times the class hours of the easiest (our arithmetic). Esperanto does not appear on the institute’s lists, which name only natural languages.
Klingon and Na’vi: languages made for the screen
Klingon has a translated Shakespeare play. The Klingon Language Institute published The Klingon Hamlet first as a limited hardbound edition of 1,000 numbered copies, plus 26 deluxe copies, and later as a Pocket Books paperback; it calls the play “the largest piece of text in Klingon to date”. “To be or not to be” becomes “taH pagh taHbe’”, literally “[one] continues or [one] does not continue,” as a post in the institute’s mailing list archive quotes it, citing Marc Okrand. The same post says Okrand had to invent the verb taH while the film Star Trek VI was being made.
Na’vi, the language of the film Avatar, was created by Paul Frommer, a professor emeritus at the University of Southern California, who still writes about it on his blog, Na’viteri. In a June 2026 post, he gave the English line “Communication is far more than a matter of words.” in Na’vi as “Tìsäfpìlyewn ke lu aylì’u nì’aw.” In September 2026 he was still adding vocabulary: “We haven’t had any new words in a long time, so here are a few to start.”
Neither source gives a number of speakers, and neither do any others we opened.
Data limits
Every Esperanto figure here is an estimate or a self-report: UEA’s range and its native speaker figure are undated, Wandel’s figure is modeled from Facebook profiles in a paper received in April 2014, and the census count covers Hungary in 2011 only. They are not ranked or combined. The learning hours are the institute’s usual timelines for its own students, not a promise for any learner. “About four times” and “about 3 to 4 times” are our arithmetic.
The short version
Esperanto, published in 1887, has no exact speaker count. UEA says hundreds of thousands and possibly millions have some knowledge of it, and as many as a thousand are native speakers. Wandel’s 2015 paper estimates about two million users on the internet alone. Hungary’s 2011 census counted 8,397. Na’vi is still gaining words, but for it and Klingon we found no published count of speakers.
Last checked: 2026-10-20, against the Universal Esperanto Association, INDECS (Wandel 2015), Hungary’s 2011 census, the US Department of State’s Foreign Service Institute page, the Klingon Language Institute and Na’viteri.org. This article was machine-checked against the sources above and has not been expert-reviewed. Spotted an error or a newer public figure? Please tell us on our contact page with the article link and we will review it.
Sources
- S1 Universal Esperanto Association, “Ĝisdate pri Esperanto” (English information page). https://www.uea.org/info/en/ghisdate_pri_esperanto . Accessed Oct 20, 2026.
- S2 Amri Wandel, “How Many People Speak Esperanto? Or: Esperanto on the Web,” Interdisciplinary Description of Complex Systems (INDECS) 13(2), 318 to 321, 2015 (received April 28, 2014; abstract read). DOI 10.7906/indecs.13.2.9. http://indecs.eu/index.php?p=318-321&s=x&y=2015 . Accessed Oct 20, 2026.
- S3 Hungarian Central Statistical Office (KSH), 2011. évi népszámlálás, 3. Országos adatok, table 1.1.4.2 (language knowledge by sex), p. 59. https://ksh.hu/docs/hun/xftp/idoszaki/nepsz2011/nepsz_orsz_2011.pdf . Accessed Oct 20, 2026.
- S4 US Department of State, “Foreign Language Training” (Foreign Service Institute). https://www.state.gov/foreign-language-training/ . Accessed Oct 20, 2026.
- S5 Klingon Language Institute, “The Klingon Hamlet.” https://www.kli.org/activities/kli-press/the-klingon-hamlet/ . Accessed Oct 20, 2026.
- S6 Klingon Language Institute, tlhIngan Hol mailing list archive, June 6, 2013, message 30 (“Klingon Word of the Day: taH”), quoting KGT page 194 by Marc Okrand. https://kli.org/tlhIngan-Hol/2013/June/msg00030.html . Accessed Oct 20, 2026.
- S7 Paul Frommer, Na’viteri.org, About page and home page posts of June 20 and September 30, 2026. https://naviteri.org/about/ and https://naviteri.org/ . Accessed Oct 20, 2026.
- Method: “about four times” and “about 3 to 4 times” are Book of Odds arithmetic from the figures above.