About This Tool
The Clarity Index is a tool that was developed by the US Army to encourage personnel to be more clear with their writing.
In the business/academic world, the Clarity Index is an amazingly simple way of checking if you are making things too complicated, or if you are being too abrupt.
It does this by using a combination of the average words per sentence (aim for 15) and the percentage of your total text that are "long words" (aim for 15%).
The actual calculation is a bit complicated - and can take more than a minute to perform if you do it manually. This tool takes just seconds.
Copy a chunk of text - e.g. part of an e-mail or a report, between 180-200 words - and you will see the Clarity Index. Aim for 20-40, with 30 being ideal.