How easy (or difficult) is your work to read? This is a question that can be answered to some degree with the Flesch–Kincaid readability tests, which (in very simple terms) are designed to provide a readability score and indicate what grade-level education is needed to understand the work.

The purpose of this post is to explore how and if the Flesch–Kincaid readability tests are useful to writers (well, this writer anyway). Why am I using the Flesch–Kincaid readability test when there are other readability tests out there? Simple. Flesch–Kincaid comes with MS Word, so most writers have access to it and are probably familiar with it. To get the Flesch–Kincaid readability scores in MS Word do the following. File > Options > Proofing > Show Readability Statistics. Then, simply run a spelling/grammar check on your document. When it finishes, you’ll get a popup box with your readability scores (plus a bunch of other numbers that factor into those scores).  We’ll be focusing on three numbers:

• Passive Sentences – The percentage of passive sentences in your work.
• Flesch Reading Ease – This is a score between 0 and 100 that indicates how easy or difficult your work is to read. Higher is easier.
• Flesch-Kincaid Grade Level – This is a score, usually between 1 and 12 (but can be higher), that indicates the years of education someone would need to understand the work

So, now that we know what these number mean let’s take a closer look at what might influence these scores. Note, I might compare my scores to those of famous authors referenced in a very in-depth article on this subject by Shane Snow (and in my own research), but I am in now way inferring I write as well (or as successfully) as these authors. All I’m saying is that based on some raw stats, there may be similarities in things like sentence length and word choice (stuff the Flesch-Kincaid readability scores take into account).

One thing that tends to influence readability scores in my stories is the amount of dialog in them. So let’s look at a couple of pieces and see if that pans out.

1) “A Point of Honor” published by Radix Media

• Passive Sentences: 1%
• Flesch Reading Ease: 86.6
• Flesch-Kincaid Grade Level: 3.7

“A Point of Honor” is a 5,000-word near-future sci-fi/horror piece. Looking at the readability scores, a couple of things jump out at you. Grade level and reading ease are very high, in the same ballpark as Hemingway. Why is that? Well, out of of the story’s 544 sentences, 191 of them are dialog, around 35%. I do my best to write dialog like people might actually talk, and that generally means shorter sentences, simpler language, and so on, which is reflected in the readability stats. Now, let’s see if that changes in a story without a lot of dialog.

2) “Paint-Eater” published by The Arcanist 

• Passive Sentences: 1%
• Flesch Reading Ease: 78.3
• Flesch-Kincaid Grade Level: 5.8

This is a 3,800-word horror story, and looking at the stats, it’s still pretty readable, somewhere around Stephen King and Stephanie Meyer. Out of this story’s 257 sentences, only 29 are dialog, about 10%. The lack of dialog here means I have to tell the story in a different way. It’s more descriptive and introspective, which for me means more complex sentences, multisyllabic words, and so on. That lowers my readability score. Of course, these scores are still well within the parameters for popular fiction, but the lack of dialog does change my stats in a noticeable way.

What else might influence my readability scores? How about genre? Let’s take a look at two more stories and see what that looks like.

1) Acts of War III: Stormbreak published by Privateer Press

• Passive Sentences: 3%
• Flesch Reading Ease: 72.3
• Flesch-Kincaid Grade Level: 6.8

This is roughly 20,000 words of steampunk fantasy, and as you can see, it yields my densest prose yet. Now why might that be? Fantasy, especially steampunk, is filled with jargon and pseudo-technical words. This piece is littered with words like necromechanikal and Vindicator warjack and annihilator axes, which, uh, all have more than a few syllables. In addition, even when there’s dialog, these words tend to pop up because they’re important to the story. Also, the folks talking are trained experts in various fields from magic to military, which can increase sentence length and complexity. All of that adds up to lower readability scores. Now, compared to some genres, like lit-fic, and authors, like, say, Lovecraft, this is still incredibly readable stuff, but you can see how genre can affect readability. Let’s check out another piece and another genre.

2) “The Back-Off” to be published by On-Spec Magazine

• Passive Sentences: 1%
• Flesch Reading Ease: 82.5
• Flesch-Kincaid Grade Level: 4.6

“The Back-Off” is a crime/noir/urban fantasy mash-up, but I think it shares more stylistic elements with the first two genres than the last. As you can see, readability goes way up, and I think that’s due to a couple of things. One, the story’s primary characters aren’t the type to wax poetic in dialog, and there is a lot of dialog in this one. Two, there’s a fair bit of action in this story, and I generally write action with short sentences and short paragraphs to convey urgency and motion. Those two things equal lower readability scores. Now, does everyone write crime fiction this way? Of course not, but a quick a dirty look at some excerpts available online showed me that Michael Connelly’s scores are in this range, as are Elmore Leonard’s.

One question I think is important is can you use these readability scores in real time when you’re writing a story? I think so, and they can be a useful tool if you’re going for a very specific voice. Case in point, I published a story a while back called “Where They Belong,” which is from the first-person perspective of a six-year-old boy, and I wanted the language to reflect that. Here are the readability scores on the final version of that story:

• Passive Sentences – 0%
• Flesch Reading Ease – 94.1
• Flesch-Kincaid Grade Level – 2.7

Pretty simplistic, and that’s what I wanted. As I was writing, I would grab a passage, run it through Flesch-Kincaid, and see how complex it was. If I got reading ease and grade levels that felt too high, I’d go and see if I could simplify the prose a bit more. You could do this the other way as well. If you’re writing a story and you want a character to sound particularly erudite, you might check and see if their dialog is scanning a bit lower on the readability scale. Of course, this is just one factor of getting a character’s voice right, but it can be a useful data point.

So, what does all this mean and should you worry about these scores? I’d say if your work is falling somewhere between 60 and 90 for reading ease and between 4 and 9 for grade score, you’re probably in good shape. That’s gonna put you within the norms for most published adult fiction (from Shane Snow’s article and the separate research I’ve done). That said, I think the Flesch-Kincaid readability scores can be useful when you’re trying to get a handle on whether or not your work is consistent with what readers expect from a genre. I don’t think you should look at these numbers as hard and fast rules for how to write any genre, but they can be one more piece of data that helps you target markets more effectively. For example, if you’re writing middle-grade fiction and getting readability scores in the 50s and grade levels in the low teens, maybe it’s time to take a look at your prose. That’s an extreme example, but I think you get the idea.

If you’d like to know more about how Flesch-Kincaid readability scores are calculated, the Wikipedia entry is actually a great place to start.

This is just the tip of the iceberg when it comes to what might influence a story’s readability scores. For example, POV might be a factor, as would something obvious like a writer’s personal style, but what I referenced above is where I tend to use them in my own work. You might find another use for these numbers, and if you have, I’d love to hear about it in the comments.