Sentence Count Calculator

Sentences are detected by finding occurrences of sentence-ending punctuation: full stops (.), question marks (?), and exclamation marks (!). The counter groups consecutive punctuation marks (such as '...' or '?!') as a single sentence end. Abbreviations like 'Dr.' or 'U.S.' may cause slight over-counting, but the result is accurate for standard prose.

Most writing style guides recommend an average sentence length of 15 to 20 words for good readability. The US Plain Language Guidelines recommend sentences averaging 20 words or fewer for government documents. Journalism typically aims for 15 to 18 words per sentence. Shorter sentences are generally easier to read, but variety is important: mixing short punchy sentences with longer ones keeps the reader engaged.

This calculator rates average sentence length as: Concise (under 15 words), Optimal (15-20 words), Moderate (20-25 words), or Complex (over 25 words). 'Optimal' aligns with plain language writing best practices and suits most audiences. 'Complex' does not mean the writing is bad, just that it may challenge casual readers. Academic and legal writing often has longer average sentence lengths by necessity.

Paragraphs are blocks of text separated by one or more blank lines (double line breaks). A single continuous block of text with no blank lines counts as one paragraph. Empty lines at the start or end of the text are ignored.

The Flesch-Kincaid readability formulas measure how easy English text is to read. The Flesch Reading Ease score ranges from 0 to 100 (higher is easier). The Flesch-Kincaid Grade Level maps text to a US school grade level. Both use average sentence length and average syllables per word. This calculator provides sentence length guidance aligned with the principles behind Flesch-Kincaid.