How Long Should a Sentence Be? Genre Benchmarks

01

The short answer

Four numbers, then the table.

Medians of the median document, computed from the corpus. Each finding below is a citable sentence.

22.6words per sentence, median document across all genres
16.6 to 28.5genre medians, marketing (SaaS pages) to corporate (press releases, filings)
33%of sentences run over 25 words, median document
1.81syllables per word, median document

The median document across all 3,470 runs 22.6 words per sentence; genres range from 16.6 in marketing (SaaS pages) to 28.5 in corporate (press releases, filings).
Whiskers in the chart are the middle half of documents in each genre; the CSV adds bootstrap 95% intervals of the mean.
The 15-to-20-word target that the Plain English Campaign, Canada.ca and the Nielsen Norman Group recommend describes 3 of the 9 genres: marketing (SaaS pages), fiction, technical documentation.[3][7][8]
Everything written to inform rather than to tell a story or sell runs longer: news, encyclopedia, government and corporate prose all sit above 20.
Press releases and filings carry the longest sentences, 28.5 words with 48% of sentences over 25 words; fiction the shortest at 17.5 with 22% over 25.
Gunning measured business prose at about 26 words in 1968 and called it 'geared to the early 1800s'. It has not moved.
Word length separates genres as sharply as sentence length: academic abstracts average 2.01 syllables per word and 30% words of three or more syllables; fiction averages 1.36 syllables and 8%.
Every classic formula is built from these two numbers, which is why abstracts score a median Flesch-Kincaid grade of 17.4 with sentences no longer than news.
News prose runs 23.0 words per sentence, longer than every magazine group Gunning charted in 1968 (15 to 20) and than COHA's 2000s newspapers (16.7).[2][17]
Our news slice is wire-service and public-broadcaster copy, which runs to full, attributed sentences; headlines and briefs are excluded.
Paragraphs are a different unit on the web and on the page: public-domain novels run a median 64.0 words per paragraph, web pages between 20.2 and 30.8.
The US federal guidelines' ceiling of 150 words and Yoast's orange light at 150 would flag the median nineteenth-century novel paragraph and pass almost every web page.
On the engine's four-dimensional grade, measured on 474 sampled documents, the genres rank government 7.3, technical documentation 8.3, academic abstracts 8.7, marketing (SaaS pages) 8.9, corporate (press releases, filings) 10.1, news 10.7, encyclopedia (Wikipedia) 11.3, fiction 11.6, legal (court opinions) 11.6.
Where the engine grade diverges from Flesch-Kincaid, the cause is vocabulary or clause structure that sentence length does not capture.
Court opinions and government rules are not the longest-sentenced genres: 20.1 and 23.7 words, below news, but with the highest shares of passive sentences outside the encyclopedia, 23% and 14%.
Contracts are another matter: Schiess measured 42 words per sentence in an 837,000-word contract corpus against 17 in everyday English.

02

Sentence length

Where each genre sits against the targets.

Bars are the median document's average sentence length; whiskers span the middle half of documents. The dashed lines are the three numbers most often quoted as rules.

Words per sentence by genre

9 genres, 3,470 documents

Average sentence length per document, then the median and quartiles across documents in the genre. Sentences are split on terminal punctuation; headings, list items and tables were removed before counting.

03

All benchmarks

Every genre and subgenre, every measure.

Medians of documents. Filter by genre, sort any column, open a row for quartiles, intervals, the other formulas and the engine sample.

Writing benchmarks by genre and subgenre

React docs Technical documentation	43	15.8	9.1	7.7	11.8	–
Marketing (SaaS pages)	200	16.6	15.4	10.8	4.7	–
SaaS homepages Marketing (SaaS pages)	200	16.6	15.4	10.8	4.7	–
Federal appellate (F.3d) Legal (court opinions)	26	17.3	25.4	11.1	17.8	–
Fiction	143	17.5	21.6	7.1	12.5	–
Public-domain fiction Fiction	143	17.5	21.6	7.1	12.5	–
US Supreme Court Legal (court opinions)	14	17.8	29.7	11.4	21.3	–
GOV.UK guidance Government	150	19.4	19.8	10.6	20.6	–
Node.js docs Technical documentation	42	19.5	21.7	10.1	34.0	–
Technical documentation	197	19.8	23.1	10.7	26.3	–
California (Cal. 4th) Legal (court opinions)	91	20.0	30.3	12.1	21.7	–
Legal (court opinions)	160	20.1	32.0	12.1	23.4	–
MDN Web Docs Technical documentation	60	20.6	25.4	11.1	36.8	–
Economics Academic abstracts	120	21.7	28.6	16.6	14.3	–
Psychology Academic abstracts	299	21.7	28.6	17.1	27.8	–
Medicine Academic abstracts	148	22.0	30.4	16.2	32.3	–
Encyclopedia (Wikipedia)	200	22.1	32.1	12.1	31.6	–
Wikipedia featured articles Encyclopedia (Wikipedia)	200	22.1	32.1	12.1	31.6	–
Statistics Academic abstracts	120	22.4	33.3	18.3	16.7	–
Computer science Academic abstracts	87	22.6	28.6	16.5	11.1	–
Public health Academic abstracts	150	22.7	32.1	18.2	28.6	–
Mathematics Academic abstracts	117	22.8	40.0	14.3	11.1	–
News	255	23.0	40.0	13.4	20.0	–
Academic abstracts	1,714	23.0	33.3	17.4	20.0	–
VOA news News	253	23.0	40.0	13.4	20.0	–
Government	301	23.7	31.3	14.1	14.1	–
Kubernetes docs Technical documentation	47	23.9	30.6	13.5	24.7	–
Biology Academic abstracts	268	24.0	40.0	19.3	14.3	–
Social sciences Academic abstracts	146	24.0	36.6	18.0	22.2	–
Physics Academic abstracts	120	25.2	42.9	18.0	18.2	–
Humanities Academic abstracts	139	25.6	44.4	17.2	20.0	–
Corporate (press releases, filings)	300	28.5	47.6	17.6	23.1	–
Press releases (8-K exhibits) Corporate (press releases, filings)	300	28.5	47.6	17.6	23.1	–
Federal Register: Proposed rules Government	87	29.3	38.5	16.8	12.5	–
New York (N.Y.3d) Legal (court opinions)	29	29.4	48.4	15.6	33.3	–
Federal Register: Final rules Government	58	33.6	43.3	18.3	11.2	–

Showing 36 of 36 rowsRows without a subgenre line are whole genres; the rest are their subgenres (ten or more documents each). Passive share is from the Passive Voice Index detector. The Orwellix column is the median engine grade on a seeded sample of documents per subgenre.

04

Paragraph length

Words per paragraph, books against web pages.

The main corpus stores documents without paragraph breaks, so paragraph benchmarks come from two other Orwellix studies whose texts keep them: public-domain books and the web crawl.

Words per paragraph by corpus
			Middle half
News homepages State of Web Readability crawl	27	20.2	17.8 to 27.9
SaaS homepages State of Web Readability crawl	439	20.5	17.4 to 24.7
Top-1,000 homepages State of Web Readability crawl	258	22.3	17.8 to 28.0
SaaS pricing pages State of Web Readability crawl	190	22.3	18.2 to 28.0
Help-center articles State of Web Readability crawl	65	24.1	18.2 to 33.4
University homepages State of Web Readability crawl	348	28.6	23.4 to 35.6
US federal government pages State of Web Readability crawl	203	30.8	21.9 to 43.0
Children's books (public domain) Reading Levels of Famous Books corpus	40	48.9	41.8 to 62.9
Short stories (public domain) Reading Levels of Famous Books corpus	17	61.3	46.6 to 87.8
Novels (public domain) Reading Levels of Famous Books corpus	188	64.0	54.2 to 85.1
Nonfiction books (public domain) Reading Levels of Famous Books corpus	37	129.2	104.4 to 179.9

Showing 11 of 11 rowsTargets for comparison: US federal guidelines 150 words at most (never 250); GOV.UK five sentences; Canada.ca three sentences; Yoast orange at 150 words, red at 200; Microsoft three to seven lines.

05

What the guides say

Twelve targets, as published.

Each row quotes the source's own sentence. 'Tool' rows are thresholds a product applies; 'rule' rows are house standards; 'guideline' rows are advice.

Published sentence and paragraph length targets
	Sentences	Paragraphs	Unit
Plain English Campaign guideline	Average of 15 to 20 words	—	average words per sentence
GOV.UK rule	Split sentences over 25 words	No more than 5 sentences	words; sentences
US federal plain language guidelines guideline	No numeric target on the current pages	No more than 150 words in three to eight sentences; never longer than 250 words	words; sentences
Canada.ca style guide rule	Optimal under 15 to 20 words	No more than three sentences	words; sentences
Yoast SEO tool	Flag when more than 25% of sentences exceed 20 words	Under 150 words green; 150 to 200 orange; over 200 red	words; share of sentences
Hemingway Editor tool	Yellow at four or more grade levels above the US adult average; red at six or more (its own grade, not a word count)	—	grade level
Flesch guideline · 1949	17 words = 'Standard' (Reading Ease 60 to 70, 8th and 9th grade); 8 or fewer = 'Very Easy'; 29 or more = 'Very Difficult'	—	average words per sentence plus syllables per 100 words
Gunning guideline · 1968	Average under 20 words for mass-audience writing; explicitly 'a principle, not a rule'	—	average words per sentence plus share of three-syllable words (Fog Index)
SEC Plain English Handbook guideline · 1998	'Short sentences'; its annotations flag 40+, 50+, 60+, 85+ and 90+ word sentences; the model rewrite's longest is 36	'Paragraphs are short and readable'	words
Nielsen Norman Group guideline · 2017	No more than 15 to 20 words	One idea; one or two sentences is fine	words; sentences
Grammarly guideline · 2020	No word count; aim for Flesch Reading Ease 60 or higher	—	Flesch Reading Ease
Microsoft Writing Style Guide guideline · 2023	'Short sentences', no number	Three to seven lines	lines

Showing 12 of 12 rowsMartin Cutts' 15-to-20-word advice and the Associated Press guide's 16 or 17 are widely quoted but could be verified only in secondary sources, so they are not in the table.

06

Earlier measurements

What corpora measured before, back to 1949.

Published averages, quoted as given. Methods differ: some count every sentence of a million-word corpus, some a few passages.

Prior measurements of sentence length
		Words per sentence	Source
British National Corpus, written books and periodicals (ratio derived by us)	n.d.	about 18.0 words per s-unit; spoken conversation about 6.9	[19]
Five mass-circulation US magazines	1949	18 words per sentence	[1]
US magazines by group (Gunning's chart)	1968	Class 20; news 18; Reader's Digest 16; slicks 16; pulps 15; no magazine over 22	[2]
Business prose	1968	about 26 words	[2]
Brown Corpus, 54,724 sentences of 1961 American English	1980	18.49 mean; informative prose 18.6 to 24.2; imaginative prose 12.8 to 17.6	[18]
Average web page view	2008	593 words; users read at most 28% of them	[9]
Briefs before the New York Court of Appeals, by decade	2013	17.8 (1969-78), 15.9, 20.4, 34.7 (1999-2008)	[23]
Psychiatry journals, 504 articles, 2002 to 2013	2015	median 22 to 27 words per sentence by journal	[21]
Scientific abstracts, 709,577 from 123 journals, 1881 to 2015	2017	sentence length rising steadily after 1960; share of abstracts with Reading Ease below 0 up from 14% (1960) to 22% (2015)	[20]
Commercial contracts, 837,000 words, vs everyday English	2022	42 words per sentence vs 17	[22]
US presidential inaugural addresses	2022	Washington 1789: 60; Lincoln 1865: 26; Bush 2005: 22; Trump 2017: 15	[24]
COHA, 2000s decade, by genre	2025	fiction 12.1; newspaper 16.7; magazine 17.1; nonfiction 19.9; scripts (1990s) 8.6	[17]
COHA, 1810s decade	2025	magazine 27.3; nonfiction 28.0; fiction 11.1	[17]

Showing 13 of 13 rows

The long-run story is shrinkage: Rudnicka's count of 19.8 million COHA sentences has magazine prose falling from 27 words in the 1810s to 17 in the 2000s[17], and Liberman's parse of inaugural addresses runs from Washington's 60 to Trump's 15[24]. The benchmarks above land where those series end, with two exceptions that the earlier work also found: scientific writing, whose sentences have lengthened since 1960[20], and legal drafting, where a contract corpus averaged 42 words against 17 for everyday English[22]. For what sentence and word length do and do not predict about difficulty, see the Readability Score Reference.

07

Method, limitations, data

How the benchmarks were computed.

Method

The sentence and word benchmarks use the corpus of the Passive Voice Index: 3,470 public documents in 9 genres and 27 subgenres, collected from arXiv, PubMed, OpenAlex, Project Gutenberg, Wikipedia, the Federal Register, GOV.UK, software documentation, court opinions, SEC filings, wire news and SaaS marketing pages. Every document was processed the same way.

Sentences are split on terminal punctuation followed by a capital; headings, bullets, tables and code were removed first. Words are letter sequences; syllables use one dictionary-free heuristic for every document.
Each measure is computed per document, then summarised as the median, quartiles and mean across documents, with a 1,000-resample bootstrap interval for sentence length, Flesch-Kincaid and passive share.
Paragraph benchmarks come from the famous-books and web-readability corpora, where paragraph breaks survive. The Orwellix grade is measured on a seeded sample of documents per subgenre, first 1,000 words each.

Limitations

Genres are defined by source, not by hand classification; the subgenre rows show how much a genre's sources differ from each other.
Fiction is public-domain prose, mostly pre-1930; its sentence length is a classic-fiction benchmark, not a contemporary one.
Academic rows are abstracts, which are denser than full papers.
The sentence splitter is heuristic. Abbreviations and quoted dialogue cause some over- and under-splitting; the same splitter was used for every genre, so comparisons hold better than absolute values.
Syllable counts are heuristic; expect about a third of a grade of disagreement with dictionary-based tools on the formula columns.

Data and files

Tables and charts are CC BY 4.0: reuse them with a link to this page.

08

Sources

26 documents, each one opened.

The style guides and tools whose targets are quoted, and the corpus studies whose measurements are compared.

Flesch, R. (1949). The Art of Readable Writing. Harper & Brothers; archive.org scan, Reading Ease table pp. 149-150 and 'Our Shrinking Sentences'. SourceOpened 23 Oct 2026
Gunning, R. (1968). The Technique of Clear Writing, revised edition. McGraw-Hill; archive.org full text, 'Keep Sentences Short' and 'Readability Yardsticks'. SourceOpened 23 Oct 2026
Plain English Campaign (n.d.). How to write in plain English. plainenglish.co.uk free guide. SourceOpened 23 Oct 2026
Government Digital Service (n.d.). Writing to GOV.UK standards: use clear language. guidance.publishing.service.gov.uk. SourceOpened 23 Oct 2026
Vincent, S. (Government Digital Service) (2014). Sentence length: why 25 words is our limit. Inside GOV.UK blog, 4 Aug 2014; comprehension percentages attributed to the American Press Institute (secondary). SourceOpened 23 Oct 2026
US General Services Administration (n.d.). Plain language guidelines: clear and short. digital.gov (the former plainlanguage.gov guidelines). SourceOpened 23 Oct 2026
Government of Canada (n.d.). Canada.ca Content Style Guide, 2.6 Use short sentences and paragraphs. design.canada.ca. SourceOpened 23 Oct 2026
Loranger, H. (Nielsen Norman Group) (2017). Plain Language Is for Everyone, Even Experts. nngroup.com, 8 Oct 2017. SourceOpened 23 Oct 2026
Nielsen, J. (Nielsen Norman Group) (2008). How Little Do Users Read?. nngroup.com, 5 May 2008. SourceOpened 23 Oct 2026
Microsoft (2023). Microsoft Writing Style Guide: scannable content. learn.microsoft.com (vendor). SourceOpened 23 Oct 2026
Yoast (n.d.). Why and how to write shorter sentences for SEO (the sentence length check). yoast.com (vendor). SourceOpened 23 Oct 2026
Yoast (n.d.). Paragraph length check. yoast.com (vendor). SourceOpened 23 Oct 2026
Hemingway Editor (n.d.). Free readability checker: how sentences are flagged. hemingwayapp.com (vendor); thresholds stated in grade levels. SourceOpened 23 Oct 2026
Grammarly (2020). How to Use Readability Scores in Your Writing. grammarly.com (vendor). SourceOpened 23 Oct 2026
US Securities and Exchange Commission (1998). A Plain English Handbook. sec.gov PDF; margin annotations on sample filings. SourceOpened 23 Oct 2026
Wylie Communications (n.d.). How long should a sentence be?. wyliecomm.com (vendor; comprehension figures attributed to the American Press Institute, secondary). SourceOpened 23 Oct 2026
Rudnicka, K. (2025). Variation of sentence length across time and genre. arXiv:2502.04321 (pre-final of a 2018 chapter); COHA, 19.8 million sentences. SourceOpened 23 Oct 2026
Kučera, H. (1980). Computational analysis of predicational structures in English. COLING 1980; Brown Corpus, 54,724 sentences. SourceOpened 23 Oct 2026
British National Corpus (n.d.). BNC User Reference Guide: design of the corpus. natcorp.ox.ac.uk; w-unit and s-unit counts, ratios derived by us. SourceOpened 23 Oct 2026
Plavén-Sigray, P., Matheson, G. J., Schiffler, B. C., & Thompson, W. H. (2017). The readability of scientific texts is decreasing over time. eLife 6:e27725; 709,577 abstracts. SourceOpened 23 Oct 2026
Barbic, D., et al. (2015). Readability assessment of psychiatry journals. European Science Editing 41(1):3-9; 504 articles. SourceOpened 23 Oct 2026
Schiess, W. (2022). Readable Contracts, Part 3. University of Texas legal-writing blog; re-analysis of Martínez, Mollica and Gibson's corpora. SourceOpened 23 Oct 2026
Gallacher, I. (2013). 'When numbers get serious': a study of plain English usage in briefs filed before the New York Court of Appeals. Suffolk University Law Review 46(2). SourceOpened 23 Oct 2026
Liberman, M. (2022). Historical trends in English sentence length and syntactic complexity. SHEL 12 slides, 20 May 2022. SourceOpened 23 Oct 2026
Lancaster University (n.d.). Ling 131: Authorial and text style (Ellegård norm). teaching passages of 4 to 11 sentences; not corpus-scale. SourceOpened 23 Oct 2026
Kincaid, J. P., Fishburne, R. P., Rogers, R. L., & Chissom, B. S. (1975). Derivation of new readability formulas for Navy enlisted personnel. Research Branch Report 8-75. SourceOpened 23 Oct 2026

09

Cite and track

Cite this page.

Cite this page

APA

Orwellix. (2026). Writing Benchmarks by Genre. Orwellix. https://orwellix.com/resources/writing-benchmarks-by-genre

Plain

Writing Benchmarks by Genre (Orwellix, 2026): https://orwellix.com/resources/writing-benchmarks-by-genre

First published 25 Oct 2026. Reuse the tables and charts with attribution under CC BY 4.0.

Changelog

25 Oct 2026First edition: sentence, word and syllable benchmarks for nine genres and 27 subgenres from the Passive Voice Index corpus, paragraph benchmarks from the famous-books and web-readability corpora, published targets from 12 style guides and tools, and 13 prior corpus measurements.

10

Questions

The questions this page gets asked.

01What is the average sentence length in English writing?

It depends on the genre, which is the point of this page. In our corpus the medians run from the mid-teens in fiction and marketing copy to the high twenties in press releases and filings. The Brown Corpus of 1961 American English averaged 18.5 words per sentence; the written part of the British National Corpus works out at about 18. Most style guides' 15-to-20-word target describes the middle of that range, not a law.

02How long should my sentences be?

Match the slice closest to what you are writing, then look at the spread, not just the average. Gunning, who wrote the Fog Index, warned against 'a ceiling placed on sentence length'; GOV.UK's rule is to split sentences over 25 words; Yoast flags a page when more than a quarter of its sentences pass 20. The table gives the median and the share of long sentences for each genre, so you can see what readers of that genre already tolerate.

03Are sentences getting shorter?

Yes, over centuries. COHA shows magazine sentences falling from about 27 words in the 1810s to 17 in the 2000s and nonfiction from 28 to 20; presidential inaugurals went from 60 words (Washington) to 15 (Trump). Scientific abstracts are the exception: their sentences have lengthened since 1960 and their readability has fallen.

04How long should a paragraph be?

The US federal plain-language guidelines say no more than 150 words in three to eight sentences and never more than 250; GOV.UK says five sentences; Canada.ca says three; Microsoft says three to seven lines; Yoast turns orange at 150 words and red at 200. Our measured medians for web pages and for fiction are in the table.

05What is a good passive-voice rate?

Nothing like the 10% that editing tools default to, for most genres. The Passive Voice Index measured 3,353 documents and found medians from about 5% of sentences in marketing to over 30% in encyclopedia prose. The passive column here comes from that study.

06Why report Flesch-Kincaid alongside the Orwellix grade?

Because Flesch-Kincaid is what most tools print, and it is computed from exactly two of the benchmarks on this page: words per sentence and syllables per word. The Orwellix grade, measured on a sample of documents per genre, reads four dimensions of each sentence and so shows where length and syllables stop explaining difficulty.

Measure your own draft against its genre

The free Orwellix readability checker reports sentence length, passives, adverbs and qualifiers alongside one grade on four dimensions, with the hard sentences marked. Ten checks a day, no account.

Open the free checker

The Self-Editing Checklists

Five one-page checklists, one per format

Get the download

All resources · The Passive Voice Index · The State of Web Readability

How long should a sentence be? Benchmarks by kind of writing