Sentence Counter
Count sentences instantly and see your average sentence length — the single best predictor of how readable your writing feels.
About this tool
Sentence count matters less than sentence length. Readability research consistently shows that average sentence length is the strongest single factor in how difficult text feels: 14 words per sentence reads as easy, 21+ as difficult.
This counter detects sentence boundaries at terminal punctuation (. ! ? …) followed by a new sentence, and shows your average words per sentence plus your longest sentence — the one most worth splitting.
For most web writing, aim for an average of 15–20 words per sentence, and mix short punchy sentences with longer ones for rhythm.
Everything runs locally in your browser — your text is never uploaded, stored, or shared.
Frequently asked questions
What counts as a sentence?
Any run of text ending in a period, exclamation mark, question mark, or ellipsis. Text after the final punctuation mark also counts as a sentence, so incomplete drafts still count correctly.
What is a good average sentence length?
For general audiences, 15–20 words. Above 25 words on average, most readers start losing the thread. Legal and academic writing runs longer; marketing copy runs shorter.
Do abbreviations like "Dr." break the count?
Abbreviations ending in a period can register as a sentence boundary, so counts on text heavy with abbreviations may run slightly high. For typical prose the count matches manual counting closely.