Sentence and paragraph length

Two numbers on the counter panel do more editorial work than any of the others: average words per sentence, and paragraph count. Neither is a target to be hit. Both are diagnostics, and they are most useful when you know what a normal reading looks like.

Sentence length, by kind of writing

The historical drift is real and worth knowing about. Average English sentence length has fallen from roughly forty words in the sixteenth century to under twenty today. Neither end of that is a decline in standards; it reflects changes in who read and how.

Variation is the thing to aim at

A page where every sentence is eighteen words long is harder to read than one that mixes eight and thirty, even though the averages are identical. The reason is rhythm: uniform length gives a reader no signal about which sentence matters, so everything arrives at the same weight.

The practical version of this advice: after a long, complex sentence that has done a lot of work, write a short one. It lands. That is the entire technique, and it is why the average is a weaker signal than most editing tools imply.

When a long average means something specific

If your words-per-sentence figure is well above the norm for what you are writing, the cause is usually one of four things, and each has a different fix:

• Stacked subordinate clauses. The sentence qualifies itself three times before it gets to the verb. Fix: find the main clause, put it first, and make the qualifications into separate sentences.
• Buried lists. Four or five items joined by commas and a final and. Fix: make it a list. Readers scan lists and re-read prose.
• Hedging. Each qualification is individually reasonable; six in one sentence is unreadable. Fix: decide what you actually think and say it, then qualify once.
• Compound joins. Two complete sentences held together by and because they arrived at the same time. Fix: a full stop.

Paragraphs

A paragraph is a unit of thought, not a unit of length. The conventional guidance — three to five sentences — describes what one idea usually takes to develop in print, and it is a symptom rather than a rule.

Screen reading changes the arithmetic. A paragraph that looks reasonable on paper becomes an intimidating block on a phone, where the same text occupies far more vertical space in a narrower column. Two to four sentences is a better working range for the web, and one-sentence paragraphs are legitimate for emphasis provided they are rare enough to still signal something.

Signs a paragraph should be split

• It contains the word however or but at a genuine turn in the argument.
• You could write a subheading for its first half and a different one for its second.
• It runs past about 150 words.
• You lose track of the subject while reading it aloud.

Signs paragraphs should be joined

• Several consecutive one-sentence paragraphs that are not doing emphasis.
• A paragraph that begins by referring back to the previous one and adds nothing else.
• Text that looks like a list of statements rather than an argument.

Using the counter for this

The panel below every counter shows words per sentence and paragraph count together, which is the pairing that tells you the most. A high words-per-sentence figure with a low paragraph count is dense prose that will lose readers. A very low words-per-sentence figure with a high paragraph count is fragmented writing that has stopped showing how its ideas connect.

Then read it aloud, because the numbers will tell you that something is wrong and only your ear will tell you where. There is more on what the derived scores can and cannot see in readability scores explained.

Common questions