The Flesch Kincaid Readability Test measures two aspects of a document – the reading ease and grade level. Reading ease is measured from 0 to 100, 0 being incomprehensible and 100 being easily understandable by an average 11 year-old student. The reading level represents the number of years of education needed to understand the text.

It’s an automated test though and is far from perfect. There’s no straightforward way to measure the quality or comprehensibility of the writing, so it bases the scores on perceived complexity. The average sentence length and number of syllables per word are used to compute the readability score and grade level. For example, the paragraph below scores 100 on reading ease with a second grade reading level even though it’s meaningless gibberish.

The for the way is it for way to me I go to the store. The for the way is it for way to me I go to the store. The for the way is it for way to me I go to the store. The for the way is it for way to me I go to the store. The for the way is it for way to me I go to the store. The for the way is it for way to me I go to the store.

In spite of it’s failings, it can be useful as a broad gauge of how well your writing matches the reading level of your intended audience. Here are a few ways to compute the two scores.

Microsoft Word – Tools -> Options -> Spelling and Grammar or Word Options -> Proofing and check “Show readability statistics”. Spellcheck the document to see the scores. (if “Show readability statistics” is grayed out, enable “Check grammar with spelling”)

Open Office – Not supported natively. Add-ons exist.

Google Docs – Tools -> Word count (or Ctrl-Shift-C)

Added Bytes – Online form where you paste the text and get the score.

Fight the Bull – Another online form (the also have a software counterpart).

Edit Central – Yet another online form

Juicy Studio – Online tool that tests a URL.

I ran this lawyer’s gibberish through Added Bytes and it received 8.10 for reading ease and a 21.3 grade level. It’s a shame that some of the most important documents we deal with are the hardest to read.

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Here are the results of running a random post from several popular web sites through Added Bytes. The sites are ordered by grade level, highest to lowest.