Sentence Counter
Count sentences in your text instantly. Also shows words, characters, and readability scores.
Files processed in your browser — never uploaded to our serversReadability Scores
What is Sentence Counter?
A sentence counter counts the number of complete sentences in your text — each ending with a period, exclamation mark, or question mark. Beyond simple counting, sentence analysis is a core input to readability formulas: both the Flesch Reading Ease score and the Flesch-Kincaid Grade Level use average sentence length (words per sentence) as a primary variable. Very long sentences — those exceeding 30 words — dramatically lower readability scores and increase cognitive load for readers. Sentence count is also relevant to academic writing, where assignments may specify a minimum number of sentences per paragraph, and to content editing, where spotting unusually long or short sentences helps improve the flow and pacing of a piece.
How to use
- Paste your text into the input area — sentence count updates automatically.
- Read the sentence count and note the average words per sentence figure.
- Identify your longest sentences — these are the best candidates for splitting to improve readability.
- Aim for an average of 15–20 words per sentence for general audiences.
- Edit sentences directly in the box and watch the average update in real time as you revise.
Why it matters
Research by Nielsen Norman Group shows that online readers skim rather than read — averaging only 20–28% of words on a page. Short, varied sentences reduce cognitive load and keep readers engaged longer. Varying sentence length also creates natural rhythm: writing composed entirely of short sentences feels choppy and robotic, while all-long sentences feel dense and exhausting. The sweet spot for most audiences is a mix — mostly 8–15 word sentences with occasional short punches for emphasis and longer sentences for detailed explanation. Checking sentence count helps you audit pacing and catch paragraphs that have grown unwieldy during editing.
Pro tip
In business writing, target an average sentence length of 15–20 words. Academic writing can go up to 25–30 words but should compensate with clear paragraph structure and topic sentences. If your average sentence length is above 25 words, find the longest 30% of your sentences and split each at a natural conjunction or clause boundary — most readers will not notice the change, but comprehension measurably improves.