Measure the Readability of Your Documents and E-mails

One of the things I have learned very quickly as a project manager is that, what cannot be measured cannot be improved. Since most of my time is spent communicating with all the people involved in my projects via e-mail messages, documents and presentations, my question was: "How to measure the readability of my daily communication in order for me to improve it?". After a bit of digging on the internet I have found that the answer is quite simple. You configure Microsoft Office to check it automatically using measures such as: the Passive Sentences Test, Flesch Reading Ease and Flesch-Kincaid Grade Level. In this article I will show you what these measures are, why they are useful and how to enable them in Microsoft Office 2007.

How readable are YOU?

The Passive Sentences Test

The Passive Sentences measures the readability of your text as the ratio of passive sentences over active sentences. The formula used to calculate it is:

Passive Sentences Score = Number of Passive Sentences / Number of Active Sentences

The score is expressed as a percentage of passive sentences found in your text. The lower the score, the better. Active sentences are always easier to read and understand, thus making your message more persuasive.

Recommendation: your aim should be to score as close as possible to 0% . If you have a score bigger than 50% you should definitely review & update your text.

Flesch Reading Ease

The Flesch Reading Ease is the standard test of readability used by the U.S. Department of Defense for its documents and forms. It indicates how easy it is to read a given material. The formula used to calculate it is:

Flesch Reading Ease = 206.835 - 1.015 * (total words / total sentences) - 84.6 * (total syllables/total words)

The results can be between 0 and 100. The higher the score, the easier it is to understand what you have written. As you can see from the formula, the results will be lower if you use very long sentences which contain long words. One way to score higher is to use shorter sentences.

The results can be interpreted as following:

  • 0-29 - very confusing & hard to read
  • 30-49 - difficult to read
  • 50-59 - fairly difficult
  • 60-69 - standard
  • 70-79 - fairly easy
  • 80-89 - easy
  • 90-100 - very easy

Recommendation: it is better to have a score of 60 or more. Even for business documents, a score of 60 is very achievable and it takes only a few edits to obtain it.

Flesch-Kincaid Grade Level

The Flesch–Kincaid Grade Level measure translates the Flesch Reading Ease measure to a grade level. The grade level means the number of years of education generally required to understand a text. For example, a score of 9.4 would indicate that the text is expected to be understandable by an average student in the 9th grade. The formula used to calculate it is:

Flesch-Kincaid Grade Level = 0.39 * (total words/total sentences) + 11.8 * (total syllables/total words) - 15.59

Recommendation: the lower the score, the better. However, for most business documents, a score of 7.0 to 8.0 is a good target. What I noticed is that, the more abbreviations you use, the lower both scores will be. Limiting the usage of abbreviations will make you score higher and people will not have such a hard time when reading your messages and documents.

How To Enable Readability Measures in Microsoft Word 2007

First, click on the Office Button and then go to Word Options, as shown below.

Word Options

In the Word Options window, go to the Proofing section. In that section, check the option which says 'Show readability statistics' and click on OK.

Word Options

Once this option is enabled, you can check the readability of any text by pressing the F7 key. Microsoft Word 2007 will first make a spell check of the selected text and, at the end, it will show you the readability statistics.

How To Enable Readability Measures in Microsoft Outlook 2007

In Microsoft Outlook 2007, the procedure is slightly different. First, go to Tools -> Options.

Outlook Options

In the Options window, go to the Spelling tab. It is a good idea to check the two available options: 'Always check spelling before sending' and 'Ignore original message text in reply or forward'. By enabling these options, Outlook will always check the correctness of your e-mails before sending them.

Once you have done this, click on the 'Spelling and AutoCorrection' button.

Outlook Options

In the Editor Options window, go to the Proofing section. Check the option which says 'Show readability statistics' and click on OK.

Outlook Options

Now, before sending an e-mail message, Outlook will first make a spell check of your message and then will show you the readability statistics. If you did not check the 'Always check spelling before sending' option from the Spelling tab, Outlook will not check automatically the readability of your message. You can do this manually by pressing the F7 key before sending the message.

Readability Statistics

NOTE: The readability statistics are not available for Powerpoint and Excel. You won't find them in the configuration options. In Microsoft Office 2003, the readability statistics are available only in Word.


After using these measures, I managed to visibly improve the way I communicate via e-mails and documents. I now use less passive sentences, my e-mails are much more actionable, the sentences are shorter and easier to read and understand. Plus, I completely dropped the use of abbreviations. If you have found other effective ways to improve the way you communicate, don't hesitate to share them by leaving a comment.

Related content:

Communicating Data in a Visual Way
Forgotten Attachment Detector - Goodbye Forgotten Attachments To E-mails

External Links:

The Flesch Reading Ease Readability Formula
Readability Scores
Flesch-Kincaid Readability Test


Very good post, thanks a lot.

Nice information shared here.It proved to be Very helpful to me.