Here is a site that estimates a "readability score" for any sample of text that you enter, but it only works for English-language text:https://readability-score.com/text/
Does anyone know of similar sites that grade text samples in other languages? Knowing the grade level of a text will not tell you how close you are to the magical 98% threshold that Nation recommends, but you could try reading books at various grade levels, see how difficult they are for you, and eventually identify what your ideal grade level is in your target language. For pleasure reading, you obviously want a level that is easy for you to read. For language acquisition, Stephen Krashen claims that you want a level of "i+1," meaning just a bit beyond
easy for you, i.e. with a word that is new to you every once in a while.
Graded reader series try to spare you the effort of figuring out a text's difficulty level by labeling it for you, sometimes not very precisely, and different publishers use different grading systems. You are right, unfortunately, that they tend to be very expensive for what they are. No one wants to pay US$7-20 (or more with shipping) for a slim book that they will probably read only once and then, as they advance in proficiency in that language, will not need or want to read ever again. However, there is a way around this. If your local library offers an Interlibrary Loan service
, you can borrow many graded readers for free. This has already saved me hundreds of dollars. Most interlibrary loans require you to fill out a detailed request form, so you will need to have the publication information (title, author, ISBN number, etc.) at hand ahead of time, as well as the OCLC number, which you can get off of http://www.worldcat.org/
for almost any book. Not all libraries can acquire all titles, since it depends on availability and agreements between library systems, but I've had success in getting about two-thirds of the graded reader titles that I've requested. Once they located a book for me in Canberra, Australia and shipped it all the way to Phoenix, Arizona for me to borrow for just one month--and I didn't have to pay a cent! (Make sure you return everything on time in excellent condition, and be very nice to the library staff. Interlibrary Loan [ILL] is a privilege that can be rescinded from sloppy or negligent borrowers.)
Contact your library to see if they have this service. If you live in or near a big city, go to the main or central library, not to a branch in the system. Most large university libraries also have an ILL desk or department. You may as well avail yourself of this "free" service, since you have already paid for it in the form of taxes. It's the perfect solution for books that you want to read, but not buy or own (or write in).