Divide multi-syllable words by word total, multiply by 100 for percentage, add average sentence length and multiply by 0.4 and the result is the Fog Index for that particular piece of writing. Fog Index A Fog Index over 13 is drifting into a fog but results can be fallible - commonsense is the ultimate test. The enemy air was fading. A Fog Index of 7.2 is sparklingly clear. Some Tips P refer the familiar word to the far-fetched.
P refer the single word to circumlocution.
N ouns and verbs carry more weight than adjectives and adverbs and so choose verbs and nouns that stand on their own without showy adverbs and adjectives. C hoose a short word in preference to a long one, as long as it is appropriate. V ary length of sentences, preferably - short, shortish and long in a crescendo effect. V ary sentence-openings to change subject emphasis and to vary the pattern of sentences. Catching the reader's attention with sentence-openings is important.