Sentence Length Calculator
Sentence Length Shapes How Text Feels to Read
A string of long, clause-heavy sentences reads very differently from short, punchy ones, even when both convey the same information. Average sentence length is one of the simplest measurable style indicators, and it's also a direct input into most readability formulas — a text's words-per-sentence figure alone explains a large part of how easy or hard it feels to read.
The Formula
Alongside the average, this calculator also reports the longest and shortest sentence in the text by word count, since a high average can hide a mix of very short and very long sentences rather than uniformly medium-length ones.
Where This Matters
- Editing for rhythm and pace — varying sentence length deliberately, rather than defaulting to one length throughout, generally makes prose more engaging to read.
- Spotting run-on sentences — the longest-sentence figure flags outliers that might benefit from being split.
- Style guide compliance — some publications and technical writing standards set a target maximum average sentence length.
How to Use This Calculator
- Paste or type your text into the text box.
- Select Calculate to see average words per sentence, plus the longest and shortest sentence lengths in the text.
Related Calculations
Sentence length feeds directly into the Flesch Reading Ease Calculator and Gunning Fog Index Calculator, both of which use it as part of their readability formula.