Boost Your Email ROI By Improving Your Readability

Email marketing remains a popular digital marketing tool, and for good reason. Consumers love it, and it's effective: in fact, email marketers can expect an average ROI of $38 for every dollar spent. Effective email promotions engage your prospects, entice them to click on your CTA, and convert. If your own email marketing efforts aren't paying off in these ways, it's time to take a good look at your readability.

What is Readability and Why Should You Care?

Today's consumers have shorter attention spans than ever before. The average attention span these days is only about 8 seconds. That's how long you have to grab a prospective customer's attention with your email.

When someone on your email list gets an email from you, it has to compete against all of the other emails they've received, plus news, their social media accounts, sports stats, and all the other content they have at their fingertips. The average office worker receives a whopping 121 emails a day. They only open 34% of them, and the average email click-through rate is only around 3%. It's hard to break through the chaos and actually capture attention with your email promotions.

One key to snagging attention and making your email the exception is to improve your email readability. Readability is just what it sounds like: how readable is your email? Is it concise, clear, and to the point? Can a customer skimming your email quickly understand what you're saying, and feel intrigued enough to click on your CTA?

Email with high readability has these features in common:

  • Concise instead of wordy
  • Doesn't involve a lot of overly long sentences
  • Doesn't use long words when a shorter, simpler word will do
  • Uses active voice instead of passive voice
  • Doesn't use cliches

If your email has a high degree of readability, it's engaging, easy to grasp, and fun to read. Emails with low readability tend to be boring, convoluted, and difficult to understand. And those emails tend to end up in the trash before your reader gets past the first few lines.

Increasing your readability can seriously boost your email ROI. Customers are more likely to open, read, and click through on a highly readable email. Improving readability is a great way to counteract short attention spans and the problem of customers mentally checking out before they finish reading your email.

So, How Do You Calculate Readability?

Knowing how important readability is isn't much help if you don't know how to calculate it. Luckily, there are readability formulas to help determine the readability of any piece of content. The Flesch-Kincaid Grade Level is probably the most respected and well-known readability formula at this time. The Flesch-Kincaid Grade Level is even used at government agencies like the Department of Defense, ensuring government materials are easy to read and understand.

Other readability formulas include Flesch Reading Ease, the New Dale-Chall, and Gunning Fog. Each formula takes a slightly different approach to measuring readability. was designed to make it super easy to find out how readable your content is, including emails. Simply copy and paste an email into the text box and click "Measure Readability." You can also upload files instead of copying and pasting. You instantly receive a readability grade, plus a breakdown by readability formula.

Improving Readability

Now that you know how to measure your email readability, it's time to make improvements. offers simple and easy to follow suggestions just below the grade. The areas that need improvement are also highlighted or underlined in different colors, depending on the issue. There is a simple legend to guide you, and you can also hover over text to see what the issue is.

Simply follow the suggestions and then rescore until you get a higher grade. Here are a few readability best practices to keep in mind:

  • Use shorter sentences. Aim for under 30 syllables.
  • Use shorter, easier to understand words. Saying "burdensome" or "herculean" when you could simply say "difficult" or (better yet) "hard" is silly and can be off-putting for readers.
  • Read your email out loud to make sure it's clear and makes sense. Don't focus so much on readability that you end up with a choppy email that's missing words or transitions.
  • Switch from passive voice to active voice - an easy primer can be found here.
  • Don't neglect your subject line. Remember that only 34% of emails are actually opened. A highly readable, snappy subject line is an email marketer's best friend.


One of the best things about measuring readability is that it changes how you write. After correcting a few emails, you will soon find yourself writing in a more concise and readable way. Remember that your customers and prospects are busy people. They will most likely skim your email and only read around 20-28% of the actual words. Be clear, be concise, and make every word count!

Check Your Readability!

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Dave Child

Dave is the founder of, and has been building websites since the early 90s. He's one of those fortunate people who gets to do what he loves for a living.


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