How Long Is a Sentence? Average Sentence Length
There is no fixed length for a sentence. A sentence can be one word (“Stop.”) or more than a hundred. For clear writing, a good aim is an average of about 15 to 20 words, with most sentences under 25. The UK government’s style guide for GOV.UK tells writers to “try to split up sentences that are over 25 words long”.
So “how long is a sentence” really has two answers: how long sentences are in real writing, and how long they should be for readers. Below we measured both, using three well-known texts and our free Sentence Counter, which shows the length of every sentence you paste in.
What counts as a sentence?
A sentence is a group of words that makes a complete statement, question or command. In writing, it starts with a capital letter and ends with a full stop (period), question mark or exclamation mark.
Length is usually counted in words. That is what style guides mean when they talk about sentence length, and what our tool reports.
How long sentences are: three real examples
We pasted three texts into our Sentence Counter on 12 November 2026:
| Text | Sentences | Words | Average length | Middle (median) length | Longest | Over 25 words |
|---|---|---|---|---|---|---|
| Pride and Prejudice, chapter 1 (1813) | 59 | 853 | 14.5 words | 10 words | 79 words | 8 (14%) |
| US Declaration of Independence (1776) | 44 | 1,324 | 30.1 words | 24 words | 128 words | 21 (48%) |
| GOV.UK guidance “Use clear language” (today) | 71 | 953 | 13.4 words | 13 words | 36 words | 4 (6%) |
The two older texts came from Project Gutenberg. In the GOV.UK page, each line of a bullet list counts as its own sentence, which pulls its average down a little.
What the numbers show:
- Averages hide a lot. Jane Austen’s chapter averages 14.5 words, but half its sentences are 10 words or shorter, mostly quick lines of dialogue. Its longest sentence is still 79 words.
- Formal 18th-century writing ran long. Almost half the sentences in the Declaration are over 25 words, and one is 128 words.
- Modern plain English is short and even. The GOV.UK page averages 13.4 words, and its longest sentence is 36.
How long a sentence should be
Most style guides agree on the direction, if not one exact number:
- GOV.UK says to “try to split up sentences that are over 25 words long” and to keep paragraphs to no more than 5 sentences, in its writing guidelines. Plain English is mandatory for all of GOV.UK.
- Why it matters: the same GOV.UK page cites literacy studies showing, for example, that 1 in 6 adults in England have very poor literacy skills. Shorter sentences help everyone, including specialists, who the page says also prefer plain English.
A good working rule:
- Aim for an average of 15 to 20 words.
- Keep most sentences under 25 words.
- Mix lengths. A run of sentences that are all the same length reads flat, whether they are all short or all long.
A sentence-length guide by type of writing
| Type of writing | Our suggested aim |
|---|---|
| Instructions, forms, public information | Short: mostly under 20 words |
| Web pages and blog posts | Average about 15 to 20 words |
| Business emails and reports | Average about 15 to 20 words, few over 25 |
| Academic essays | Can be longer, but split anything you have to read twice |
| Fiction and dialogue | Anything goes, and short lines of speech pull the average down |
These are rules of thumb, not fixed limits. The real test is whether a reader understands the sentence the first time.
Check your own sentence length
- Open our Sentence Counter.
- Paste your text. It counts your sentences and words and shows your average, longest and shortest sentence.
- Look at the list below the numbers. Every sentence over 25 words is flagged, so you can see which ones to split.
A tip from our test: paste text in normal paragraphs. When we first pasted the Gutenberg text, which has a line break every 70 characters or so, the tool found 103 “sentences” in Austen’s chapter instead of 59, because a line break inside a paragraph looks like a sentence end. Text copied from PDFs and some emails has the same problem. Join the lines into paragraphs first, or the averages will be too low.
How to shorten a long sentence
- Split at “and”, “but”, “which” or a semicolon. Long sentences often contain two ideas joined together.
- Cut filler. “In order to” becomes “to”. “Due to the fact that” becomes “because”.
- Use the active voice. “You need a passport” is shorter and clearer than “A passport is needed”.
- Turn a list into bullet points. If a sentence lists four or more things, a list is easier to scan.
- Read it aloud. If you run out of breath, the sentence is too long.
Summary
- A sentence has no fixed length, but under 25 words is the common limit for clear writing.
- Aim for an average of 15 to 20 words, with a mix of short and longer sentences.
- In our test, Pride and Prejudice chapter 1 averaged 14.5 words, the Declaration of Independence 30.1, and a GOV.UK guidance page 13.4.
Check your writing with our free Sentence Counter. For the next level up, see how many sentences are in a paragraph and how many paragraphs are in an essay.