How readable is your writing?

7th Mar 2006

Have you ever considered how easy it is to read and understand what you write and publish on your site? I'm not just referring to literacy or eloquent writing, I'm referring to the average number of words you use in a sentence and how many syllables those words contain; yes, I'm talking about Flesch grading. If you publish your own material or consider yourself to be an accessible web designer, it's a subject worth considering.

Roger Hudson, Russ Weakley and Peter Firminger collaborated on a study to highlight the importance of thinking about users with cognitive disabilities and learning difficulties. They advise the use of content control, which means offering a long and a short version of your writing (although this should probably only apply to technical texts). The ultimate rule they advise:

Keep it short. People don't 'read' web pages in the same way they read printed documents. Website visitors rely heavily on skimming and scanning techniques to find areas of interest quickly.

And keeping it short really is the key: short sentences and short words. And this is where Flesch grading comes in.

What is Flesch grading?

In the 1940s, Rudolf Flesch produced some readability formulas for authors to use when producing school textbooks. Applying these formulas would result in a Flesch score (often referred to as Flesch Reading Ease). This score relies on syllables and sentence lengths to determine the reading ease of a text. Unfortunately, the downside of Flesch grading is it doesn't take meaning into account, so in theory it's possible for your writing to achieve a high readability score, but still to be difficult to understand.

The table below should give the grading a clearer context:

Flesch scoreDifficulty levelAverage sentence lengthSyllables
100Very easy to read12No words of more than two syllables.
60Plain English15 to 20Average word has two syllables.
0Extremely difficult to read37Average word has more than two syllables.

Right, here's the scientific bit: to calculate a Flesch score (Flesch Reading Ease) you take the sentence length in words and multiply it by 1.015. Then the number of syllables per 100 words is multiplied by 0.846. These two numbers are added together and their sum is then subtracted from 206.8. Got that? Good.

Put simply, about 20 words per sentence with an average of 1.5 syllables per word gives a Flesch score of 60 and is classed as plain English. The higher the score, the easier the text is to understand.

Grade your own writing using Microsoft Word

You can use Flesch grading to calculate how readable your own writing is by using Microsoft Word. First of all, you may have to change a setting to Show readability statistics. Here's how to do it:

  1. From the top menu, choose Tools
  2. Then Options
  3. Select the Spelling and Grammar tab
  4. Under the Grammar heading check the show readability statistics box
  5. Click OK

Then all you need to do to view your readability statistics is select Tools > Spelling and Grammar or use the shortcut key F7.

Other options for calculating your Flesch Reading Ease

Useful links

accessibility