SpeedFactor: How is readability score calculated?

In order to evaluate the effectiveness of your writing, you can easily check the readability of your website pages. Key scores, such as Flesch-Kincaid reading ease and grade level, will help you determine if your writing is reaching the right audience.

What is Flesch-Kincaid readability?

Developed by Rudolf Flesch and J. Peter Kincaid, the Flesch-Kincaid readability scores are the most widely used measures of readability. And they are used by the United States military to evaluate the readability of their manuals.

The first number, Flesch-Kincaid reading ease, is based on a ranking scale of 0-100, and the higher your score, the better. Low scores indicate text that is complicated to understand. So if your website receives a low Flesch-Kincaid reading ease score, you will likely need to simplify your text.

For most business writing, a score of 65 is a good target, and scores between 60 and 80 should generally be understood by 12 to 15 year olds.

Flesch-Kincaid reading ease formula: 206.835 – 1.015 x (words/sentences) – 84.6 x (syllables/words).

The second number, Flesch-Kincaid grade level, tells you the American school grade you would need to be in to comprehend the material on the page.

As a measure, most of your writing should be able to be understood by students in seventh grade.

For example, The Huffington Post’s website has an average grade level of about 7, meaning that it should be easily understood by 12 to 13 year olds.

Flesch-Kincaid grade level formula: 0.39 x (words/sentences) + 11.8 x (syllables/words) – 15.59.

Both Flesch-Kincaid reading ease and grade level use the same core metrics: word length and sentence length. But they correlate inversely. If you receive a high score on the reading ease test, you should receive a lower grade level score.

A readability score is a number that tells you how easy or difficult it is to read your text. The idea behind it is that people read at different levels and something that is absolutely readable for a PhD can leave pupils’ heads spinning.  A readability score is based on the Flesch-Kincaid test of readability and is currently available for English only.

The higher the readability score the easier the text is. Scores can be interpreted as shown in the table:

Why does readability matter?

If your text is too complicated and hard to understand, people will leave your page and return to the search results. On the other hand, if your text scores a very low grade level, users will likely assume that your content isn’t valuable. Both of these things can prevent site visitors from interacting with your content and contribute to a high bounce-rate.

In order to maximize your readership, it’s important for the content on your website to reflect the readability expectations of your audience.

Catering to the readability expectations of your audience will help keep people on your site, and ultimately increase conversions.

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