Why Average Sentence Length Matters
Average sentence length is the quickest single proxy for readability — it drives most classic readability formulas, including Flesch Reading Ease. For clear everyday writing, aim for 15–20 words per sentence on average. News agencies drill journalists to stay near 17; plain-language guidelines for government and health writing recommend 20 or fewer. Once your average creeps past 25, most readers start losing the thread mid-sentence, and under about 12 the writing can feel choppy and abrupt. The fix is rarely to shorten every sentence — it's to vary them, letting one long sentence carry an idea and a short one land it.
The counter above splits sentences at ending punctuation (periods, exclamation marks, question marks). Abbreviations like "Dr." and decimals like "3.5" can occasionally add a phantom sentence, so treat the figure as a close estimate rather than gospel. For full text statistics — characters, reading time, speaking time — head back to the main word counter, or check your text against platform caps with the character counter.
Sentence Length Benchmarks
| Writing Style | Typical Avg Words / Sentence | Feel |
|---|---|---|
| Ad copy, headlines | 5–10 | Punchy, urgent |
| News reporting | 15–18 | Clear, brisk |
| Blog & business writing | 15–20 | Conversational |
| Fiction | 12–25 (varies widely) | Rhythmic, varied |
| Academic writing | 20–30 | Dense — often too dense |