The ‘Flesch–Kincaid’ or ‘text readability’ test is designed to show how difficult it is to read – and therefore to understand – the content. It was developed for the U.S. Navy, as such, the original formula works primarily for English. Try the link below for your worksheets (just paste in your text) and look at how hard it is to read for students. You can also use this test in Microsoft Word too.
Here are some tips about supporting students with prepared text https://www.changepeople.org/getmedia/923a6399-c13f-418c-bb29-051413f7e3a3/How-to-make-info-accessible-guide-2016-Final