bloggers guide to readability

4 Blog Readability Tips That Will Make Your Readers Stay On Your Site

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Last Updated on May 6, 2020

A well-written blog can do wonders for your business as well as for your personal brand. It can propel your blog even if your niche isn’t business related. However, a quality post goes beyond just making sure you’ve addressed your audience’s pain points or showing them how to achieve something.

bloggers guide to readability

If you’ve been blogging for awhile, you’ve probably learned a thing or two about optimizing your posts for search engines. But did you know that readability plays a role in how well your post is optimized for SEO?

Just like keywords, the title, and the meta description; the readability of your post matters too. When your post is easy to read and understand, your readers are more likely to read it all the way to the end. It might even encourage them to move on to the next post.

So how exactly do you determine the readability of your posts? And what is readability anyway?

What Is Readability?

Put simply, readability is the ease with which a reader can understand the written text.

The language you use, the length of your sentences, and even your grammar; all have an impact on the readability of any written text.

Readability is measured with a readability score calculated by the computer. It tells you what level of education a reader will need to understand your text. The lower the education level needed, the easier your text is to understand.

statue reading
Readability scoring predates the web.

Readability has been studied since the 1880s when English professor L. A. Sherman found that the English sentence was getting shorter, declining from 50 to 23 words. However, it wasn’t until the 1920s that researchers became more concerned with the ease of reading.

It was around that time that educators noticed that textbooks had too many technical terms in them. In 1921 Edward Thorndike, a psychologist from Columbia University, noticed that Russian and French teachers used word frequency counts to decide which books were appropriate for which students.

Based on that idea, he published Teacher’s Word Book. It contained the frequencies of 10,000 words and made it easier for teachers to choose books that matched class reading skills.

His book led to many university-based psychologists starting their own research on what readability is as well as how it differs based on education level.

Notable Readability Research

The most notable research on readability dates to 1935, when William S Gray of the University of Chicago and Bernice Leary of Xavier College in Chicago published What Makes a Book Readable.

The book contains a reading study done on 1,690 adults from varying backgrounds.

The results showed that about one-third of the adults read at the 2nd to 6th-grade level, one-third at the 7th to 12th-grade level, and one-third at the 13th to 17th-grade level.

In the book, they also stress that 50% of the adult population didn’t have appropriate reading materials.

Their research further showed that content was most important in determining appropriateness. This is followed by style, format, and organization. Based on their findings, they came up with a reading formula based on five selected style variables:

  • The average length of sentences
  • The number of varied difficult words
  • How many personal pronouns are included
  • Percentage of unique words
  • The total number of prepositional words and phrases.

Even though their formula was based on the most scientific research at the time, it wasn’t accurate enough. It did, however, create the desire to come up with the perfect reading formula.

Another notable moment in readability research was Irving Loring’s article, which demonstrated that other variables and combinations of variables could determine the difficulty of written passages more accurately than those used by Gray and Leary. In 1944, Lorge published his Lorge Index, which used only three variables to score readability:

  • Average sentence length in words
  • Number of prepositional phrases per 100 words
  • Number of hard words not on the Dale list of 769 easy words.

It was his formula that had the most impact on readability formulas that are used today.

Smart kid smart phone
This kid is checking the readability of your blog posts.

How Readability is Measured

The readability formulas use mathematical calculations that take into account various factors such as the number of words in a sentence or the number of letters or syllables per word. Most of the formulas are based on one semantic factor such as word difficulty and a syntactic factor such as sentence difficulty.

Some of the most reliable readability tests that are used today include:

  • Flesch Reading Ease and Flesch-Kincaid Grade Level
  • Gunning-Fog Score
  • Coleman-Liau Index
  • Dale-Chall formula.

Here is an overview of each:

Flesch Reading Ease and Flesch-Kincaid Grade Level

The Flesch Reading Ease Formula was published in 1948. It relies on the structure of the English language and takes into consideration the sentence and word length to determine readability.

It uses a scale of 0-100 where a score of 100 or more means that the content is very simple and easy to read. A score of 60-70 indicates a reading level suitable for students in the 8th or 9th grade, and a score of 0-30 indicates a university reading level.

The exact formula for calculating your Flesch Readability Score is as follows:

Reading Ease = 206.835 – (1.015 × Average Sentence Length) – (84.6 × Average Syllables Per Word)

Average sentence length is calculated by dividing the number of words by the number of sentences, while the average number of syllables per word is calculated by dividing the number of syllables by the number of words.

His original formula was modified in 1967 by John P Kincaid to produce a grade-level score. The research was sponsored by the US Navy and the new formula is as follows:

Flesch-Kincaid Reading Age = (0.39 × Average Sentence Length) + (11.8 × Average Syllables Per Word) – 15.59

Nowadays, the Flesch-Kincaid Grade Level is considered to be one of the most reliable formulas to determine the readability score of a text. It has been adopted as the standard by many US government agencies, including the Department of Defense.

Gunning-Fog Score

The Gunning-Fog Score is attributed to American textbook publisher, Robert Gunning, who noted that most high school graduates were unable to read. He thought newspapers and business documents were full of unnecessary complexity. As a result, he created his own Fog Index which is based around his assumption that any word containing more than two syllables is a hard word.

His formula is very simple to apply:

Grade level = 0.4 × ( (average sentence length) + (percentage of Hard Words) )

The ideal score according to the Fog index is 7 or 8, and anything above 12 is too hard for most people to read.

Even though it’s one of the most accurate formulas, it falls short in recognizing that not all multi-syllable words are complex and hard to understand.

Coleman-Liau Index

beach reader
Actual photo of a man who gave up trying to read a “newspaper blog.”

Designed by linguists Meri Coleman and TL Liau, the Coleman-Liau Index relies on characters instead of syllables per word. They believed that computerized assessments have an easier time of counting characters and came up with the following formula:

CLI = (0.0588 × L) – (0.296 × S) – 15.8

L is the average number of letters per 100 words and S is the average number of sentences per 100 words.

Dale-Chall formula

Developed in collaboration between Edgar Dale and Jeanne Chall, the Dale-Chall formula is unique because it uses a count of “hard” words, or words that do not appear on the list of common words familiar to most 4th grade students. It originally used the Dale’s list of 769 easy words but was later expanded to include a list of 3000 familiar words:

Raw Score = ( 0.1579 × (Percentage of Difficult Words) ) + ( 0.0496 × (Average Sentence Length in words) )

The Raw Score refers to the reading grade of a reader who can understand a text at a 3rd-grade level or below.

How to Test The Readability of Your Posts

There are several tools online that will allow you to check the readability score of your posts.

  • Free Text Readability Consensus Calculator: this tool will assess your text based on the formulas above as well as The SMOG Index, the Automated Readability Index, and the Linsear Write Formula.
  • Readable: this tool will score your text according to the Flesch-Kincaid Grade Level, the Gunning-Fog Index, and other formulas. It will also give you suggestions on sentences that are too long, extra words, cliches, and more.
  • The Writer: similar to the tools above, this online checker will assess your text based on the Flesch-Kincaid Grade Level, the Gunning-Fog Index, and the SMOG Index.
    tiny reader
    Readers don’t like feeling small.
  • Hemingway Editor: while not strictly a readability checker, this app will highlight sentences that are too complex, suggest words that can be replaced or omitted, and more. Overall, it aims to make your writing simpler and eliminate all the fluff.
  • Yoast SEO: even though it’s primarily used for SEO, this WordPress plugin includes a feature that automatically tests for Flesch Reading Ease.
  • Readability Calculator: uses Coleman-Liau Index, Flesch Kincaid Grade Level, ARI (Automated Readability Index), and SMOG to score your text and it even gives you a thorough breakdown of which sentences need editing.

How to Improve Your Readability Score

If you used the tools mentioned above and walked away unsatisfied, fret not as there are ways to improve your readability score. Before jumping into editing your posts, you might want to determine the ideal readability score that would be best suited for your audience.

How to Determine Your Blog Readability Level

As with many things in blogging, your readability level falls back onto your target audience. It’s crucial to understand your audience’s background and demographic information such as their age and education level before you set out to modify anything.

If your audience is younger and your content suited for children, the higher the score the better. But if you’re dealing with a scientific topic geared toward other scientists, then a lower score is not a bad thing.

Generally, the ideal readability score is between 60-70 to ensure you will reach and engage everyone in your audience. Anything above, and your content may come off as too simple. A consistent score below 60 indicates that your writing could use some serious polishing.

Improving Your Score

Here are a few tips that will help you bring your score to the ideal level for your content and your target audience.

Keep Your Paragraphs and Sentences Short

The average paragraph length is considered to be around five sentences. Keep in mind that there are exceptions to that rule. As noted above, highly-scientific content will require longer paragraphs. As opposed to that, simple content can be broken up into even smaller paragraphs for easier reading.

Long sentences are a good way to scare off your readers so keep them short. A good rule of thumb is to use no more than 17-20 words per sentence.

Avoid Complicated and Unnecessary Words

reader arkansas
Better readability helps grow your blog’s popularity.

Use as few words as possible to convey your idea and avoid passive language. You may know some obscure or not so common words, but that doesn’t mean your audience knows them too. Simplify your vocabulary whenever possible.

Break Up Your Content

Use headers and bullet points to break up your post and make it easier to skim.

You can also break up your post into several shorter ones, especially if you’re trying to explain several concepts. Instead of one long post, try creating a series or publish more frequently.

Keep In Mind The Structure

Just like all those school papers, structure matters online, too. Keep in mind the key message of your post and what your audience needs to know before getting familiar with the main idea. This will help you organize your post in a logical way and make it easier to understand.


When you keep the readability score in mind, you will wind up writing more readable content on an almost subconscious level. Your posts will be more interesting and engaging to your audience who will be more inclined to come back to your site. Use the tips above to improve your readability and keep your readers happy.

Photo credits: Smart kid and the smart phone by Stephanie — licensed under CC BY 2.0Museum reader by Monika — licensed under CC BY-SA 2.0. Newspaper reader by Niccolò Caranti — licensed under CC BY-SA 2.0Tiny reader by Erich Ferdinand by — modified by cropping — licensed under CC BY 2.0Reader, Arkansas by gregwest98 — licensed under CC BY 2.0.

Brenda Barron is a writer from southern California. When not writing about blogging and business, she’s spending time with her family and knitting.