Readability
What Readability Score Should You Aim For?
Readability is important for communicating clearly with your audience. Learn about readability, what a readability score is, and find out what readability score you should aim for.
Your content may be well-researched with the right keywords naturally sprinkled throughout the text. However, it may fail to engage an audience if it's not readable.
A simple definition of readability is how easy it is to read a text. It’s about more than that, though. It’s also about how enjoyable it is for readers to consume your content.
People aren’t necessarily going to stick around for an article they’re struggling to read. This is why finding and achieving the right readability score for your audience is so important.
So, for best results, what readability score should you aim for? Read on to learn about readability, readability scores, and the ideal ones for the most common tests.
A readability score is a number that tells you how much education your readers need to understand your text.
Example: If the number corresponds to a 5th-grade level, it should be easy for 5th-graders to understand it.
Now, this may sound pretty straightforward, but here’s the thing, there are several ways to calculate readability. From the Flesch-Kincaid Reading Ease test to the SMOG index, each formula is different, and a good score on one may not be so great on another.
So, the readability score you should aim for can depend on the formula.
Generally speaking, you should aim for a readability score appropriate for a grade 7 to 8 reading level (keep in mind this might not correspond to the number of the score itself). However, aiming for a slightly higher grade level may work if you’re trying to rank on Google.
Our study into the best readability score to rank on Google found that most online content is written for a grade 12 education.
However, it’s important to keep in mind that different formulas can yield different results. Let’s say you use a readability checker to calculate scores using multiple formulas. You may find that a piece achieves different readability scores that vary by formula.
To help you narrow what’s a good readability score to aim for, we’re outlining some of the most commonly used readability formulas for assessing the grade level of content:
One of the most — if not the most — popular readability tests is the Flesch-Kincaid Reading Ease formula. It looks something like this:
Flesch-Kincaid Reading Ease = 206.835 − (1.015 x average sentence length) − (84.6 x average syllables per word)
To calculate average sentence length, divide total words by total sentences. For average syllables per word, divide the total syllables by the total number of words.
What’s a good readability score on the Flesch-Kincaid Reading Ease test? To rank well in Google, our readability study found it was best to aim for a score between 45 and 60.
Yes, the Flesch-Kincaid team came up with not one but two readability tests. Like the Reading Ease formula, the Flesch-Kincaid Grade Level uses the average sentence length and average syllables per word, but this time, the result directly corresponds with a US school grade level.
This is the formula:
Flesch-Kincaid Grade Level = (0.39 x average sentence length) + (11.8 x average syllables per word) − 15.59
What’s a good readability score on the Flesch-Kincaid Grade Level test? A score of 8 to 10 can reach a wide audience; for an audience with a post-graduate level education, aim for a score of 12 or lower.
Originally developed to help businesses improve their writing, researchers now use the Gunning Fog Index to help improve the clarity of their papers. Instead of using syllables like the previous two, this formula focuses on complex words and long sentences.
It looks like this:
Gunning Fog Index = 0.4 x {(average sentence length) + (percentage of hard words)}
What’s a good readability score on the Gunning Fog Index? Our analysis found that it’s best to aim for a score between 11 and 13.
If you’re creating training documents like manuals, questionnaires, and multiple-choice tests, then the FORCAST readability formula may be a good fit. Unlike the above formulas, this one doesn’t include sentences in its calculation — it’s all about the vocabulary.
Here is the formula:
FORCAST Grade Level = 20 − (number of single-syllable words in a 150-word sample / number of total words)
That’s it! There’s just one important thing to note about this one. Since the FORCAST formula was designed for technical writing, not school materials, it can’t calculate text below a 5th-grade level.
What’s a good readability score on the FORCAST readability formula? According to our readability findings, you should go for a score between 12 to 14 here.
Though there are many others, the last readability formula we’ll cover in this article is the SMOG Index. SMOG stands for Simple Measure of Gobbledygook and estimates how much education the average person would need to understand a text.
The formula for this one is a little more complex:
SMOG = 1.043 x √(total number of polysyllabic words) x 30) + 3.1291
The SMOG Index is primarily used in the legal and healthcare sectors. It was designed to start at readability levels of grade 5 (USA) or grade 4 (UK).
What’s a good readability score on the SMOG Index? Like many others, it depends on the audience you are writing for. If your audience primarily has a grade 10 or higher education, then aim for a score of 10 or below.
First and foremost, prioritize creating readable content that is easy to read and enjoy.
Using a readability checker to crunch the numbers of readability formulas is a convenient way to evaluate and edit the readability of text. Keep in mind that the best readability score depends on the audience you are writing for. Tailor your content to communicate clearly with your readers.
Now, get out there and start creating more readable content! Your audience will thank you.
