Sentence Counter
Count sentences, average sentence length and find the longest sentence in a block of text.
How Sentence Counter works
Count sentences and paragraphs, see average words per sentence and the longest sentence in your draft. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.
That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.
What counts as a sentence
Sentences are split on a full stop, question mark, exclamation mark or ellipsis, including the case where the text ends without punctuation. That is the same rule the word counter uses, so the two pages agree on the same document.
The tool also reports total words, average words per sentence, and the longest sentence in the draft — the last one is where readability problems usually hide.
Average sentence length is the readability lever
Around 15–20 words per sentence reads comfortably for general audiences. Above 25, readers start re-reading; above 35, most people skim or stop. The average hides the damage, which is why the longest sentence matters more than the mean.
One 60-word sentence in a page of 15-word sentences drags the average to 18 and still stops a reader dead. Fix the outliers, not the average.
| Average length | Reading experience |
|---|---|
| Under 12 | Choppy; may read as childish |
| 15–20 | Comfortable for most audiences |
| 21–25 | Dense but workable for informed readers |
| Over 30 | Needs splitting |
Where it goes wrong
Abbreviations with full stops — “e.g.”, “Dr.”, “etc.” — are read as sentence ends, inflating the count and shrinking the average. So are decimals in some patterns. If your text is full of abbreviations, treat the sentence count as approximate.
Headings without punctuation are not counted as sentences, which is usually correct but means a page of headings reads as having almost no sentences.
Good to know
- Works offline once loaded, including on flights and in locked-down networks.
- No file size limit beyond your device's own memory.
- Free to use, with no account and no usage counter.
- Results are produced locally, so they are not logged or shared with anyone.
Questions
How are sentences detected?
Split on full stops, question marks, exclamation marks and ellipses, so abbreviations can occasionally split a sentence.
What is a good sentence length?
For web writing, 15–20 words per sentence keeps readers moving.
Does it count paragraphs?
No — the word counter and readability checker report paragraphs. This page focuses on sentences.
Why is my longest sentence shown as a fragment?
The splitter works on punctuation, not grammar. A colon-heavy sentence can be cut in a place a human would not choose.
Keep going
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