Average Words Per Sentence

3 min read

Short answer

Modern English prose averages 15 to 20 words per sentence. Journalism sits nearer 15, academic writing nearer 25. What matters more than the average is the variation around it.

Check your own numbers

4m 12s

Reading time at 238 wpm

Reading speed

238 words per minute · average is 238

At other speeds

1,000 words
Slow reader — 150 wpm6m 40s
Average reader — 238 wpm4m 12s
Fast reader — 320 wpm3m 8s

Common lengths

250 words1m 3s
500 words2m 6s
1,000 words4m 12s
1,500 words6m 18s
2,000 words8m 24s
5,000 words21m 1s

The figures

Writing Average words per sentence
Children’s books 8–12
Tabloid news 12–16
Broadsheet news 15–20
Web and marketing copy 12–18
Business writing 15–20
Literary fiction 12–25, widely varied
Academic papers 22–30
Legal documents 30–60

For general readers, 15 to 20 is the comfortable band. Plain-language guidance in government and healthcare usually recommends aiming nearer 15 to 20, with a hard look at anything over 25.

Sentences have been getting shorter

The long-term trend in English is unmistakable. Sentences in published prose averaged around 45 words in the early 1600s, fell through the 1800s, and settled into the teens over the twentieth century. Victorian novels that feel dense to a modern reader are not badly written; they were written for readers who expected 30-word sentences and had time.

The practical consequence is that a sentence length which reads as ordinary in an older book reads as heavy today, and a reader who loses the thread of a sentence does not go back — they stop.

Why the average is the less interesting number

Two paragraphs can average 18 words per sentence and read completely differently.

One runs 18, 17, 19, 18, 18 — technically ideal and exhausting to read, because the rhythm never changes and every sentence lands with the same weight.

The other runs 6, 31, 9, 24, 20. Varied, with room to build and room to land. That is what good prose looks like when you measure it.

So the average is a screening figure. If it is over 25, you have a genuine problem. If it is under 20, look at the spread instead — which is why our readability checker shows the distribution of your sentence lengths rather than just the mean.

Long sentences are not the enemy

A long sentence that is well built is a pleasure, and it does work a short one cannot: holding several related ideas in view at once so the reader sees the relationship between them.

The problem is the long sentence that is long by accident — three clauses stapled together with “and”, a subordinate clause that begins before the subject has appeared, a list that grew mid-thought. Those are hard to read at any length, and length is what makes them hard to fix.

Two questions to ask about a 35-word sentence: can I find the subject and the verb quickly, and would a full stop halfway lose anything? If the answer to the second is no, that is where the full stop goes.

Measuring your own

The sentence counter reports your average alongside the length of every individual sentence, so you can see the shape rather than the summary. The readability checker buckets them and flags anything at 30 words or more.

A note on how the counting works, since tools differ: a sentence ends at a full stop, question mark or exclamation mark. Decimals like 3.5, initials like J. R. R. and abbreviations like “Dr.” do not end one. A semicolon joins two clauses into a single sentence, so it does not either — if you want the halves counted separately, use a full stop.

Frequently asked questions

What is a good average for a blog post? 14 to 18. Long enough to carry an idea, short enough to survive being read on a phone.

Does sentence length affect readability scores? Heavily. It is one of only two inputs to both Flesch formulas, which is why shortening sentences moves a score more reliably than swapping long words for short ones.

How many words is too many for one sentence? There is no limit, only a cost. We flag 30 words because beyond that a sentence needs to be deliberate, and most are not.

Should I worry about very short sentences? Only if there are many in a row. A run of four-word sentences reads as clipped; one in the middle of longer ones is emphasis.