For any text, you can set a readability target and then assess the text using a readability checker. Microsoft Word has a built-in readability checker for Flesch–Kincaid and Flesch reading ease scores. Several free or commercial readability checking products are also available.

Your readability target should be based on your understanding of the audience and the difficulty of the content. It is important to remember that audience engagement and understanding of a text may be influenced by several factors, including:

• English language level

• education level

• general or technical knowledge.

Your readability target will also depend on whether you have just a single type of target audience or a mixture of types. If you are communicating with only a single type of audience, the readability level of the text can be tailored for that audience. If you are communicating with several audiences, you may need to use the lowest relevant target, provide explanations for any technical content, or layer content. See Planning before you write for ideas on engaging different audiences.

Reading grades and common audiences are:

• grades 4–5 – children, adult readers with intellectual disability or cognitive problems

• grade 6 – children, readers with lower levels of education and literacy

• grades 7–8 – mixed adult audiences, including competent and not-so-competent readers; grades 7 or 8 are probably the most common targets for general or online content

• grade 9 – as for grades 7–8, with a few more technical terms and concepts

• grades 10–12 – technical and professional audiences

• grades 13–16 – technical and professional audiences, university-level content.

Take particular care in setting reading targets for readers with English as a second language. The reading skills of first-language users of English are underpinned by their familiarity with thousands of English words, idioms and sentence structures, encountered in everyday conversation and written texts of various kinds. The language skills of second-language users of English may be more limited. For these audiences, take care with word and sentence length, sentence structure, and the use of idioms and metaphors. See Knowing your audiences for more discussion on tailoring content to your audiences. You may also wish to think about using visual methods to convey information to these audiences – see Showing for more information.