Free Sentence Counter

Paste or type your text below for an instant sentence count. You'll also see your average sentence length, Flesch-Kincaid readability grade, and Flesch Reading Ease score — all updating live as you type.

Sentences

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Avg Words / Sentence

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Readability Grade

Words

Flesch Reading Ease Score

Scores range from 0 (extremely difficult) to 100 (very easy). Most general-audience writing targets 60–70.

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Paste text to see score

What Is a Good Sentence Length?

There is no single perfect sentence length — the right length depends on your audience, your purpose, and the rhythm you want to create. But research and editorial practice do give us useful benchmarks:

General prose and journalism

The Associated Press and most major news organisations aim for an average sentence length of 15–20 words. This is short enough to be immediately clear to a general audience but long enough to carry a complete thought with appropriate nuance. Sentences below 8 words can feel choppy; sentences above 30 words demand more concentration from the reader.

Online content

For web content, shorter is better. Web readers scan rather than read; they lose their place in long sentences. Many content strategists recommend an average of 14–18 words for blog posts and web pages. Short sentences — under 10 words — are especially effective for emphasis, transitions, and calls to action.

Academic and technical writing

Academic writing tolerates longer sentences because readers are typically subject matter experts willing to invest attention. Average sentence lengths of 20–30 words are common in journal articles. However, even technical writing benefits from variation — a short, punchy sentence after a long complex one creates contrast that helps readers process information.

Fiction

Sentence length in fiction is a stylistic tool. Short sentences build tension and pace. Long, flowing sentences can create a meditative or lyrical quality. The best authors vary sentence length deliberately — punchy sentences to propel action, longer constructions for reflection, mid-length sentences to establish a comfortable reading rhythm. There is no target average; variation is the target.

The power of variation

Average sentence length is only half the picture. A document with every sentence at exactly 18 words reads robotically. The most readable prose combines short, medium, and long sentences. If your sentences are all the same length, that is the problem — not the specific length itself.

Flesch Reading Ease Scale Explained

The Flesch Reading Ease formula, developed by Rudolf Flesch in 1948, produces a score from 0 to 100 based on average sentence length and average number of syllables per word. It is still one of the most widely used readability metrics in publishing, government, and healthcare.

Score	Difficulty	Typical Audience	Examples
90–100	Very Easy	5th grade (age 10–11)	Basic instructions, children's books
80–90	Easy	6th grade (age 11–12)	Simple guides, conversation
70–80	Fairly Easy	7th grade (age 12–13)	Popular fiction, consumer guides
60–70	Standard	8th–9th grade	Newspapers, general web content
50–60	Fairly Difficult	High school	Quality magazines, HR documents
30–50	Difficult	University level	Academic articles, legal text
0–30	Very Confusing	Graduate / professional	Scientific journals, legal contracts

Flesch-Kincaid Grade Level

The Flesch-Kincaid Grade Level formula converts the same inputs into a US school grade number. A score of 8 means an 8th-grader should be able to understand it. This version is used by the US Department of Defense as a writing standard for technical documentation.

Average Sentence Length by Writing Style

Writing Style	Target Avg Length	Notes
Children's books	6–10 words	Simple vocabulary, short sentences
News / journalism	15–20 words	AP Style, clarity for general public
Web content / blogs	14–18 words	Shorter preferred for scan reading
Business writing	15–20 words	Plain language guidelines recommend this range
General non-fiction	18–22 words	Room for explanation and nuance
Literary fiction	Highly variable	Style drives length; variation is key
Academic / scientific	20–30 words	Complex constructions expected by expert readers
Legal documents	Often 40+	Precision over readability; plain-language reforms push shorter

Frequently Asked Questions

How does this tool detect sentences?

The counter identifies sentences by looking for text terminated by a sentence-ending punctuation mark — a full stop (.), exclamation mark (!), or question mark (?). This covers the vast majority of written sentences in standard English prose. Ellipses and other edge cases may not be counted as sentence boundaries.

Are abbreviations counted as sentence endings?

This can cause minor over-counting. For example, "Dr. Smith went home." might be counted as two sentences if the abbreviation period is treated as a sentence terminator. For most prose this makes a negligible difference, but it is worth being aware of if your text contains many abbreviations.

What is Flesch Reading Ease and how is it calculated?

Flesch Reading Ease = 206.835 − (1.015 × average words per sentence) − (84.6 × average syllables per word). A score of 100 is easiest; 0 is hardest. The score is sensitive to both sentence length and word complexity — the two most controllable factors in readability.

What is the difference between Flesch Reading Ease and Flesch-Kincaid Grade Level?

Both use the same underlying variables (sentence length and syllable count per word) but with different coefficients and scales. Flesch Reading Ease gives a score from 0–100 where higher = easier. Flesch-Kincaid Grade Level gives a US school grade number where higher = harder. The Grade Level score shown by this tool translates the grade number into a descriptive label (Easy, Average, Hard, etc.).

Is my text stored or sent anywhere?

No. All processing happens entirely inside your browser. Nothing you type is ever transmitted to our servers.