The average divides total words by sentences. The median is the middle length after the sentence counts are sorted.
Content & publishing
See the shape of your sentence rhythm without grading the writing.
Map sentence lengths in order, inspect a fixed-band distribution, and compare the average, median, and population standard deviation. The tool describes the pattern; it does not decide whether the pacing is good.
- Runs in your browser
- Exact counts shown
- No invented score
- No signup required
Step 1 · Add a representative passage
Paste the text to inspect.
Use complete prose. Leave out navigation, tables, and interface labels unless they are part of the reading experience.
478 UTF-8 bytes1,048,576 maximum
Analysis runs in this browser. Plainview Tools does not fetch, upload, store, or send the text you enter.
Step 2 · Review the pattern
Sentence length variation
Analysis complete. 10 sentences. Average 7.9 words per sentence. Population standard deviation 4.9 words.
- Sentences
- 10
- Average length
- 7.9 words
- Median length
- 7.0 words
- Population standard deviation
- 4.9 words
Distribution
Words per sentence
Each bar shows the share of word-containing sentences in one fixed length band.
- 1–5 words330.0%
- 6–10 words660.0%
- 11–15 words00.0%
- 16–20 words00.0%
- 21–30 words110.0%
- 31–40 words00.0%
- 41+ words00.0%
View distribution as a table
| Sentence length | Sentences | Share |
|---|---|---|
| 1–5 words | 3 | 30.0% |
| 6–10 words | 6 | 60.0% |
| 11–15 words | 0 | 0.0% |
| 16–20 words | 0 | 0.0% |
| 21–30 words | 1 | 10.0% |
| 31–40 words | 0 | 0.0% |
| 41+ words | 0 | 0.0% |
Sequence
Sentence lengths in reading order
Each column is one sentence. Height represents its word count; the sequence does not rate the rhythm.
- Shortest sentence
- 3 words
- Longest sentence
- 21 words
- Within ±2 words of average
- 5 (50.0%)
Population standard deviationDivides by N = 10
This describes the spread of every sentence in this pasted passage. Sentence boundaries: Intl.Segmenter.
This is a descriptive pattern—not a pacing, readability, quality, accessibility, or SEO score.
A smaller standard deviation means lengths cluster more closely around the average; a larger value means they are more spread out. Neither result is automatically better.
What is being calculated
Center and spread, kept separate.
The same passage can have a similar average but a very different distribution. Plainview keeps the underlying counts visible so one summary number never becomes a verdict.
√(Σ(length − average)² ÷ N)
Because the pasted passage is the complete set being described, the calculation divides by its sentence count, N—not N − 1.
Fixed word-count bands show where sentence lengths gather. The sequence preserves reading order so repeated shapes remain visible.
Version 1.0 method boundary
Sentence boundaries use Intl.Segmenter when available and a conservative punctuation fallback otherwise. A final unpunctuated fragment is included.
Word lengths use Plainview Tools' shared Unicode word-counting rule, including internal apostrophes and common hyphens. Unspaced scripts use dictionary segmentation when Intl.Segmenter is available.
The seven fixed word-count buckets are descriptive. Bucket percentages and displayed summary values are rounded to one decimal place.
The within-two-words measure counts sentences whose length is no more than two words above or below the sample's unrounded average.
A smaller standard deviation means sentence lengths cluster more closely around the average; a larger value means they are more spread out. Neither pattern is rated as better.
Segmentation, statistics, and writing sources
Use the chart as evidence, not a rule.
Source check: August 24, 2026. Unicode documents sentence-boundary behavior; NIST defines common measures of center and spread. CDC guidance supplies writing context, not a universal sentence-length target.