Using Math to Boost Your Writing's Readability

Writing is a skill you never stop learning. If you care about effectively communicating with your audience, at some point, you will need to come to terms with the readability of what you write.

Readability is defined as “the quality of being easy and enjoyable to read”. Which is really not very helpful, because the definition doesn’t tell you what’s either easy or enjoyable to read.

Of those two things, what’s enjoyable for you to read is completely subjective. You might, for instance, enjoy reading works of postmodern literary criticism, although that’s very unlikely because these works are not easy to read. That’s because the writers of these works don’t care about effective communication with their audience. Their writing is mostly an exercise in vanity.

What makes something readable then comes down to how easy it is to read. Fortunately, that is something that can be quantified. Because it can be quantified, it can be measured. And once you know how ease of reading is measured, you can make your writing more readable.

Or rather, once you know how to score how readable your writing is, you can game the system to get a better readability score for your writing.

The most common measure of how easy a passage of text is to read is the Flesch Reading Score. Here’s the math that goes into how it is calculated:

Flesch Reading Score = 206.835 – 1.015 × (Total Words ÷ Total Sentences) – 84.6 × (Total Syllables ÷ Total Words)

To get the highest score possible, your writing should use:

• a low number of words, using
• a lot of sentences, and
• words that have few syllables.

If you go back and read the first paragraph of this article, it consists of 34 total words with 51 syllables in 2 sentences. It has a Flesch Reading Score of 62.7, which puts it at an 8th-to-9th grade reading level. That qualifies as “plain English”, which most English speakers would say falls in the sweet spot between being easy and difficult to read.

Now, since we know how to game the reading score, we made some very minor tweaks to produce the following paragraph:

Writing is a skill you never stop learning. If you’re a writer, at some point, you’re going to need to come to terms with the readability of what you write. At least you will if you care about communicating with your audience.

This version of the opening paragraph has 42 words, 3 sentences, and 57 syllables earn a Flesch Reading Score of 77.8. The minor changes we made dropped its difficulty level to the 7th grade level, even though we added words. The changes make it fairly easy for a larger audience to read.

Here’s some additional math you can use to get the Flesch-Kincaid Reading Level, which is mapped to the U.S. school grade level:

Flesch-Kincaid Reading Level = 0.39 × (Total words ÷ Total sentences) + 11.8 × (Total Syllables ÷ Total Words) – 15.59

Here’s the reading score-to-grade summary:

A lot of writers at the “professional” end of the grade scale make the mistake of not appreciating who the audience for their writing is. The worst writing we see is often that of “educators”. The worst offenders in this group would appear to care more about showing off how smart they are than being effective at teaching. Somehow, they just don’t get that teaching involves communicating with a much broader audience than themselves.

Image Credit: Photo by Fa Barboza on Unsplash.