Vocabulary size
How many words are there in English?
There is no single number, because each count defines a word differently. The Oxford English Dictionary has over 500,000 entries, Webster's Third New International Dictionary over 476,000, and a study of Google Books estimated about 1,022,000 English words in use in 2000. Leave out names, compounds, archaic words and related forms, and Webster's Third comes down to about 54,000 word families.
Key points
- The Oxford English Dictionary (OED) has over 500,000 entries and 3.5 million quotations. It is a historical dictionary, so obsolete words count too, and it added more than 900 new words, phrases and senses in its June 2026 update alone (OUP, 2026).
- One dictionary gives three very different numbers. Webster's Third New International Dictionary has over 476,000 entries (Merriam-Webster), about 348,000 single-word forms (Michel et al., 2011) and about 54,000 word families once compounds, archaic words, abbreviations, names, variant spellings and dialect words are left out (Nation & Waring, 1997).
- Counting words that actually appear in books gave about 1,022,000 English words in 2000, up from 544,000 in 1900. The authors estimated that 52% of them are not documented in standard dictionaries (Michel et al., 2011).
- A typical 20-year-old native speaker of American English knows about 42,000 lemmas, or 11,100 word families (Brysbaert et al., 2016), a small share of any dictionary total.
- In the 40 English books we counted, the 500 most frequent word forms make up 67.4% of all 5,631,425 running words. The long tail of rare words is what makes the totals so large.
Why is there no exact number of words in English?
Because a total depends on choices that every counter makes differently, and no authority makes them for the language as a whole. The main ones:
- Forms or headwords. Are run, runs, ran and running four words or one? Is runner a separate word? Counting forms, dictionary headwords (lemmas) or word families changes a total several times over.
- Compounds and phrases. Ice cream, give up and Web 2.0 are units of meaning, but are they words?
- Names. Every person, place and brand name would add without limit, so most counts leave proper nouns out.
- Old words. A historical dictionary keeps words no one has used for centuries; a dictionary of current English drops them.
- Specialist and rare words. Scientific names, technical terms, slang and regional words run into hundreds of thousands, and dictionaries include only those with enough evidence of use.
- New words. The total is not fixed. Dictionaries add words every year, and corpus counts change with every year of text.
So the useful question is not how many words English has, but what a particular count counts. The rest of this page goes through the main figures one by one.
How many words are in the Oxford English Dictionary?
The OED contains over 500,000 entries and 3.5 million quotations, according to Oxford University Press in its June 2026 update, which added more than 900 new words, phrases and senses, among them humblebrag, life hack and long game (OUP, 2026).
Three things make the OED total larger than a count of words people use today:
- It is a historical dictionary. It records how words have been used over the centuries, with dated quotations, and keeps words that have gone out of use.
- Entries are not all single words. The updates add words, phrases and senses together, so an entry count mixes units.
- It keeps growing. Each quarterly update adds hundreds of items, so any OED total is a snapshot with a date.
An often-quoted older figure comes from the 20-volume second edition of 1989: full entries for 171,476 words in current use and 47,156 obsolete words, plus about 9,500 derivative words as subentries (Grammarphobia, 2010). It is the likely source of the "about 170,000 words in current use" in many search results. It describes a printed edition that is more than 35 years old, and the dictionary has been revised and enlarged since.
How many words are in Merriam-Webster's dictionary?
Merriam-Webster's largest dictionary, Webster's Third New International Dictionary, Unabridged, has over 476,000 entries, with an addenda section of new words and meanings (Merriam-Webster).
The same dictionary has been counted in other units, and the totals shrink with each step:
| What is counted | Count | Source |
|---|---|---|
| Entries (the current printing also has an addenda section of new words) | over 476,000 | Merriam-Webster |
| Single-word forms (2002 printing) | about 348,000 | Michel et al., 2011 |
| Word families, without compound words, archaic words, abbreviations, proper names, alternative spellings and dialect forms | about 54,000 | Nation & Waring, 1997, from Dupuy (1974) and Goulden, Nation & Read (1990) |
The last row is the figure language-learning research uses. A word family groups a base word with its inflections and transparent derivations, such as watch, watched, watching and watcher, because a learner who knows one can usually understand the others. In that unit, the dictionary that Nation and Waring call the largest non-historical dictionary of English when it was published holds about 54,000 families.
How many English words are in use?
About a million, by the largest count of words in print. Jean-Baptiste Michel and colleagues (2011) used Google Books: 5,195,769 digitised books, about 4% of all books ever published, with 361 billion words of English. They treated a word as part of the lexicon if it occurred more than once per billion words, a frequency they say matches the words in leading dictionaries, and estimated the lexicon at three points:
| Year | English words |
|---|---|
| 1900 | 544,000 |
| 1950 | 597,000 |
| 2000 | 1,022,000 |
The authors put the growth at about 8,500 words a year. Most of the extra words are rare: when they checked a sample of the 2000 lexicon against the OED and Merriam-Webster's unabridged dictionary, excluding proper nouns, both dictionaries covered frequent words well, but 67% of words in the lowest frequency band appeared in neither. That band held 63% of the lexicon. Overall they estimated that 52% of English words in books are "lexical dark matter" undocumented in standard references, with examples such as aridification.
The study counted words as they are spelled in books, not dictionary headwords, so its million is not directly comparable with a dictionary's entry count.
A different "one million words" figure came from Global Language Monitor, a company that announced on 10 June 2009 that Web 2.0 had become the millionth English word, based on a formula that tracks how often words and phrases appear in the media. The Berkeley linguist Geoffrey Nunberg called the claim "nonsense" (Reuters, 2009). Unlike the Google Books count, it was not published as research, and Web 2.0 is a phrase rather than a single word.
How many English words are in Wiktionary?
The English Wiktionary listed 885,221 pages in its category of English lemmas when we checked on 31 October 2026 (Wiktionary). The category includes multiword terms, phrases and morphemes such as prefixes and suffixes as well as single words, and volunteers add entries every day, so the number changes constantly. It is a count of what editors have documented, not an estimate of the language.
Why do the counts differ so much?
Because they count different things. Set side by side, with the unit stated, the figures stop contradicting each other:
| Source | What it counts | Count |
|---|---|---|
| Google Books, year 2000 (Michel et al., 2011) | Words in print occurring more than once per billion, including those missing from dictionaries | 1,022,000 |
| Wiktionary (checked 31 October 2026) | Pages in the English lemmas category, including phrases and affixes | 885,221 |
| Oxford English Dictionary (OUP, 2026) | Entries, including obsolete words and phrases | over 500,000 |
| Webster's Third (Merriam-Webster) | Entries | over 476,000 |
| Webster's Third, 2002 printing (Michel et al., 2011) | Single-word forms | about 348,000 |
| American Heritage Dictionary, 4th ed. (Michel et al., 2011) | Single-word forms | 116,161 |
| Webster's Third (Nation & Waring, 1997) | Word families, without compounds, archaic words, abbreviations, names, variant spellings and dialect forms | about 54,000 |
| Median 20-year-old native speaker of American English (Brysbaert et al., 2016) | Lemmas known | 42,000 |
| The same speakers (Brysbaert et al., 2016) | Word families known | 11,100 |
If someone quotes a number of English words without saying what it counts, ask which row it belongs to. A figure of 170,000, 500,000 or a million can each be accurate for its own unit.
How many English words does a native speaker know?
Far fewer than any dictionary holds. Brysbaert, Stevens, Mandera and Keuleers (2016) tested native speakers online on words drawn from a list of 61,800 lemmas and estimated that the median 20-year-old native speaker of American English knows 42,000 lemmas, which come from 11,100 word families. Measured in families, that is roughly a fifth of the 54,000 families in Webster's Third, though the two studies define a family slightly differently. How the estimates were made, why other studies give 17,000 or 20,000, and how vocabulary grows with age are covered on how many words the average person knows.
How many English words does a learner need?
A small fraction of the language. Paul Nation (2006) estimated that knowing about 8,000–9,000 word families gives 98% coverage of novels and newspapers, the share of known words at which reading becomes comfortable, and about 6,000–7,000 families gives the same coverage of unscripted speech. That is roughly a sixth of the word families in Webster's Third. The research behind these thresholds, and what lower targets such as 95% coverage mean, is on our page about how many words you need in a foreign language. To see where you stand, our comparison of vocabulary size tests explains what each test measures.
How many different words appear in real books?
Far fewer than the dictionaries list, and a few hundred of them do most of the work. We counted the English books in the Readly library (40 books, 5,631,425 running words):
- 24.7%
- of all running words are the 10 most frequent word forms, such as the, and and of
- 52.0%
- are the 100 most frequent forms
- 67.4%
- are the 500 most frequent forms, listed with their frequencies in the 500 most common English words in books
- 17,996
- different word forms in War and Peace (Maude translation), out of 566,513 running words
Even a very long novel uses a small share of what the dictionaries list, and many of its words are rare: in the median English book in our per-book counts (37 English books), 46% of the different forms appear only once. These are counts of word forms with names included, where walk and walked are two, so they are not comparable with word-family figures. Per-book counts for 117 books in five languages are in how many different words are in a book.
How we chose the figures on this page
- Dictionary totals are taken from the publishers' own pages, checked on 31 October 2026: the OED figure from Oxford University Press's announcements of its quarterly updates (June and September 2026), which both give the same total (OUP, 2026, July 2; OUP, 2026, September 23), the Webster's Third figure from Merriam-Webster's product page.
- The 1989 OED figures could not be found on a current Oxford page; they are given with the secondary source that quotes them.
- Figures in other units (single-word forms, word families, lemmas) come from the research papers that produced them, each linked below.
- Our book figures are word forms counted in EPUB files of public-domain books, as described on how many different words are in a book.
References
- Brysbaert, M., Stevens, M., Mandera, P., & Keuleers, E. (2016). How many words do we know? Practical estimates of vocabulary size dependent on word definition, the degree of language input and the participant's age. Frontiers in Psychology, 7, 1116. doi:10.3389/fpsyg.2016.01116
- Grammarphobia (2010, March 20). Word counts. grammarphobia.com. Figures for the second edition of the OED (1989).
- Merriam-Webster. Webster's Third New International Dictionary, Unabridged: product page. shop.merriam-webster.com, checked 31 October 2026.
- Michel, J.-B., Shen, Y. K., Aiden, A. P., Veres, A., Gray, M. K., The Google Books Team, Pickett, J. P., Hoiberg, D., Clancy, D., Norvig, P., Orwant, J., Pinker, S., Nowak, M. A., & Aiden, E. L. (2011). Quantitative analysis of culture using millions of digitized books. Science, 331(6014), 176–182. doi:10.1126/science.1199644; open-access text (PMC)
- Nation, I. S. P. (2006). How large a vocabulary is needed for reading and listening? Canadian Modern Language Review, 63(1), 59–82. doi:10.3138/cmlr.63.1.59
- Nation, P., & Waring, R. (1997). Vocabulary size, text coverage and word lists. In N. Schmitt & M. McCarthy (Eds.), Vocabulary: Description, acquisition and pedagogy (pp. 6–19). Cambridge University Press. Text at lextutor.ca
- Oxford University Press (2026, July 2). What's new in the Oxford English Dictionary? June 2026 update. corp.oup.com
- Oxford University Press (2026, September 23). New to the Oxford English Dictionary this September. corp.oup.com
- Reuters (2009, June 10). "Web 2.0" named one millionth English word. Via NBC News: nbcnews.com
- Wiktionary. Category: English lemmas. en.wiktionary.org, checked 31 October 2026.