Gunning Fog Index Calculator
Calculate the Gunning Fog Index to determine years of formal education needed to understand text.
Gunning Fog Analysis
words, sentences, hard words
Gunning Fog Formula
Fog Index = 0.4 x (ASL + PHW)
ASL = Average Sentence Length (words/sentences)
PHW = Percentage of Hard Words
What Makes a Word Hard?
Hard words have 3+ syllables, excluding: proper nouns, compound words made of easy words, and words made longer by -es, -ed, -ing, -er, -ly suffixes.
Gunning Fog Index
0
years of education needed
Comparable Publications
N/A
Fog Index Guidelines
6-8: Most popular literature
8-10: Quality journalism
10-12: Professional publications
12-14: Academic writing
14+: Technical/legal documents
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Formula Source: Standard Mathematical References
by Various