The Gunning Readability Test
Created | Updated Apr 24, 2002
The Gunning Readability Test is a formula for testing how 'readable' any given piece of text is, and is particularaly useful when writing copy for brochures, textbooks, magazine articles and so on.
The test breaks down thus:
Step 1. Select a sample of at least 100 words of your text.
Step 2. Divide the number of words in your sample by the number of sentences. This will give you the average number of words per sentence.
Step 3. Count the number of words with more than three syllables. Exclude proper nouns such as place names, and verbs ending in suffixes such as -ing
Step 4. Add Average words per sentence to to number of words with more than three syllables. Multiply by 0.4 to get FOG index number.
Fog index
11-12 = readable by top 20% of age 12+
13 = readable by top 20% of age 16+
14-16 = readable by first year university level
17 = readable by university graduate level
