Our target range for readability is 5th to 8th grade. This might feel low—taxes and accounting are complex. But these lower grade levels help our users comprehend the content faster and more easily. And they support our usage guidelines on writing shorter sentences, using simple tenses, and choosing familiar words.
Simple, readable content also makes localization and translation easier. And it benefits our customers who speak English as a second language. (More than 20% of US residents don’t speak English at home.)
When scoring content, the most useful numbers to look at are the Flesch-Kincaid Grade Level and the Gunning Fog Index. The Flesch Reading Ease score is also interesting—a high number (close to 100) is better than a low number.
You can test your content using readability tools to get an idea of the grade level or years of education someone needs to understand it. Try readable.com or Writer, which has built-in readability analysis.
Tip: Microsoft Word’s spelling and grammar preferences have an option to show readability statistics when you perform a spell check. It shows both Flesch-Kincaid Grade Level and Flesch Reading Ease scores.