Write with Resonance - Use the Flesch-Kincaid Readability Tool

May 04, 2010

How to Match Your Writing to Your Audience

Readability is a critical yet often-overlooked aspect of writing – particularly online writing. Certain types of Web content are so quick and painless to post that the readability factor can easily fall by the wayside.

Readability and Your Target Audience

Every website or blog has a different target audience, of course. Some sites target a more educated demographic, some attract a population segment with specialized knowledge or expertise in a particular area, and others cater to more general audiences. The target-audience factor certainly influences the reading level, sentence structure, and specific vocabulary a writer uses to communicate his or her message.

Readability and Your Purpose

The purpose of a communication will also determine a writer's choice of writing style and difficulty level. When explaining a complex technical topic, a writer will obviously need to use a more complex writing style and less-common vocabulary. On the other hand, if a writer is penning promotional copy for a simple product and her aim is to encourage a sale, it would certainly behoove her to use a simpler, more straightforward approach.

The Flesch-Kincaid Readability Tool

Luckily, helpful evaluative tools are available to make assessing the readability of our writing easy and help us increase its readability when necessary. One such tool is the Flesch-Kincaid Readability Tool, which is based on the Flesch-Kincaid Readability Formula developed by Rudolph Flesch and John P. Kincaid.

What the Flesch-Kincaid Tool Measures

The Flesch-Kincaid tool measures reading ease using a scale of 0-100. The lower the result, the more complex the reading sample, with 60-70 generally regarded as the desirable readability level for most types of writing. The tool also assigns a grade level to each writing sample (with 7.0 to 8.0 considered the optimal level for most purposes). The two values described above are based on the following characteristics of the sample:

  • Total number of syllables to total number of words (average syllables per word)
  • Total number of words to total number of sentences (average words per sentence)

The following is an excerpt from All About Readability, by Cheryl Stephens, at Plainlanguage.com, which describes the Flesch-Kincaid scale:

The Flesch Reading Ease Scale is the most widely used formula outside of educational circles. It is the easiest formula to use, and it makes adjustments for the higher end of the scale. It measures reading from 100 (for easy to read) to 0 (for very difficult to read). A zero score indicates text has more than 37 words on the average in each sentence and the average word is more than 2 syllables. lesch has identified a "65" as the Plain English Score. In response to demand, Flesch also provided an interpretation table to convert the scale to estimated reading grade and estimated school grade completed.

The above Flesch-Kincaid values can help you determine whether the level of writing you're currently producing is appropriate to your audience, allowing you to alter it and recheck if it isn't.

Sample Readability Evaluations

I thought it might be interesting to demonstrate the tool by using it to assess the readability of two portions of this post. I've located a version of the tool at Edit Central, which I will use for illustrative purposes. (This tool happens to include measurements based on a few other readability scales, as well, though today we're focusing on Flesch-Kincaid. My next post will discuss some of the other available readability scales and tools.)

The third paragraph of this post measures as follows – which just goes to show the high opinion I have of the intelligence of Word Sell's readers!

The sample in the screenshot below measures 39.6 on the Flesch-Kincaid Readability Scale (well above average complexity) and has a 13.8 grade level (equivalent to the end of the first year of college). In my defense, let me say that one could easily consider the Flesch-Kincaid Readability Tool a complex technical topic – and the sample is, after all, rather short.

To dig myself in a little deeper, the second paragraph of this post (evaluated in the next screenshot) measures even lower on the readability scale (making it even more complex than the third paragraph), at 29.5, with a grade level of 14.2 (early second year of college). What can I say? I've always been the academic type.

For a few other samples, check out the online demos at Edit Central (link above). They provide several more Flesch-Kincaid (and other) readability evaluations that can help you get to know the tool – and your own writing – better.

A few other tools you may want to check out, which use the Flesch-Kincaid index to evaluate your writing, are the Readability Index Calculator (screenshot displayed at beginning of post) and Flesh, a downloadable desktop readability application. (Note: different tools' evaluations often differ, even when they use the same index. The Readability Index Calculator appears to return higher grade levels and lower reading ease scores than the Flesch-Kincaid results returned by the Edit Central tool.)


Personally, I've always tended toward a more complex writing style. Yet, with certain types of writing I do my best to simplify. The main point is to be aware of your target demographic and write – or revise – accordingly. The Flesch-Kincaid Readability Tool can give you the resources you need to polish your writing until it resonates with your audience.

We deliver! Sign up and we’ll send our valuable content right to your inbox.