What is the Flesch Formula? Definition and examples

The Flesch Formula or Flesch Reading Ease Formula tells us how easy or difficult a text is to read. It also tells us how difficult it is to understand. It tells us what proportion of the US population would be able to read and understand the text. Part of the Flesch Formula involves counting how many sentences a passage has per 100 words. The Formula also counts the number of syllables per 100 words.

We also call it the Flesh Reading Ease Test, Flesch Grade, Flesch Rate, or Flesch Readability Score.

Rudolf Flesch

Rudolf Franz Flesch (1911-1986), an Austrian-American readability expert, devised the Flesch Formula. He was also a writing consultant. He was a proponent of plain English in the US.

Flesch developed the Formula in the 1940s. At the time, he was a graduate student at Columbia University. He eventually earned a Ph.D. in Library Science at Columbia.

Flesch said students should use phonics to sound out unfamiliar words, rather than sight reading.

Medical-Dictionary.theFreeDictionary.com has the following definition of the Formula:

“A method of determining the difficulty of a written passage by a formulation that provides an estimate of how many people in the U.S. would be able to read and understand the passage.”

“Used in determining patient comprehension of hospital consent forms.”

Flesch Formula
The Flesch Formula initially became popular for determining the readability of school reading material. However, its popularity soon spread to government departments, hospitals, and even marketing executives.

Flesch Formula – a readability index

The Flesch Formula is a readability index. Its score ranges from zero to 100. The higher the score, the easier the text is to read and understand.

Below you can see four Flesch Formula scores and what they tell us:

  • 100 = The passage is extremely easy to read and understand.
  • 65 = The passage is relatively easy to read and understand.
  • 30 = The passage is difficult to read and understand.
  • 0 = The passage is extremely difficult to read and understand.

According to Flesch, short words and sentences are easier to read and understand than long ones.

RYTE WIKI says the following regarding the Formula scores:

“The difficulty level of a text is described depending on its structure. A high Flesch score indicates good intelligibility and readability.”

“Conversely, the readability index allows the creation of texts that are appropriate to a specific target group.”

Five W’s of Communication

The Five W’s of Communication are five words that start with the letter ‘W’. If we consider the Five W’s, our messages are more likely to have the impact we desire.

The five words are WHO, says WHAT, in WHICH channel, to WHOM, with WHAT effect?

Many Marketing executives apply the Flesch Formula to their messages. They report that a high score is more likely to produce a good result with the last ‘W’ word, i.e., with WHAT effect.

Video – Flesch Formula

Did you know that you can set Word so that it gives your text a readability score? Specifically, a Flesch Formula score. In this video, the speaker shows us how to activate the Flesch Reading Ease Tool.