<% if analysis.gunning_fog_index %>
<%= analysis.gunning_fog_index.try(:round) %> / 16 bubble_chart Gunning fog index

According to this scale, your document is <% if analysis.gunning_fog_index.round > 12 %> Understandable by a <%= (analysis.gunning_fog_index.round - 12).ordinalize %>-year college student. <% else %> Understandable by a <%= analysis.gunning_fog_index.round.ordinalize %>-grade reader. <% end %>


The Gunning fog index was developed by Robert Gunning in 1952 after working in newspaper and textbook publishing. It is primarily used to ensure that text can be easily read by a large audience. The index was refined in the 80s to more accurately measure and incorporate sentence complexity.


In general, texts intended for a wide audience are recommended to have a fog index of no more than 12. Texts requiring near-universal understanding and comprehension are recommended to keep their fog index below 8.


A higher score on this scale indicates a document is harder to understand.

To raise your score on this scale:

  • arrow_drop_up Use more words of at least three syllables.
  • arrow_drop_up Use more complex words.
  • arrow_drop_up Use longer sentences.

To lower your score on this scale:

  • arrow_drop_down Use more one- and two-syllable words.
  • arrow_drop_up Use simpler words.
  • arrow_drop_down Use shorter sentences.

<% end %>