Work out sentence length average instantly with clear inputs, formula shown and shareable results.
Average sentence length is the single strongest surface predictor of readability. Twelve hundred words in 62 sentences averages 19.4 words - moderate, with the longest sentence 2.5 times the average. Plain English guidance recommends 15-20 words on average, with deliberate variation rather than uniformity.
Average sentence length
average = total words / total sentences
Variation
longest divided by average shows how uneven the rhythm is
No. Uniformly short sentences read as staccato. Vary length deliberately and keep the average moderate.
A ratio above about three times the average usually marks a sentence trying to do too much, and it is the first candidate for splitting.