We've analysed 29,875 books from Project Gutenberg and rated each one using the same ELO system that rates your vocabulary. Find out which books match your level.
Every word in our database has an ELO rating — a precise measure of how rare and difficult it is. For each book, we find all words that appear in our corpus, collect their ELO scores, and compute the 80th percentile. That percentile becomes the book's ELO. A book rated 1600 uses vocabulary that a Lex Expert player would recognise — but a Word Apprentice would struggle with.