The Oxford Guide to Plain English recommends words per sentence. It also says: 'If you regularly exceed 40 words, you'll certainly weary and deter your readers'
Jyoti Sanyal, author of Indlish (the book for every English-speaking Indian), said: 'Based on several studies, press associations in the USA have laid down a readability table. Their survey shows readers find sentences of 8 words or less very easy to read; 11 words, easy; 14 words fairly easy; 17 words standard; 21 words fairly difficult; 25 words difficult and 29 words or more, very difficult.'
Author Ann Wylie said: 'When the average sentence length in a piece was fewer than 8 words long, readers understood 100% of the story. At 14 words, they could comprehend more than 90% of the information. But move up to 43-word sentences and comprehension dropped below 10 percent.'