How to read the table
Grades is our shelf: where a child reading on their own tends to meet the book, judged on subject matter as well as sentences. The ages column is the same span in years. Lexile and AR level are published measures of the text itself, and they only know about sentence length and vocabulary, so a book can score high and still be right for a younger child who is being read to. Peter Rabbit is the clearest case.
Every figure here was gathered from Lexile's own database, AR Bookfinder, or TeachingBooks for the unabridged edition, and where we could not find a published measure the cell is a dash. We've compared enough of these to know that the lower numbers in circulation, the 500L Christmas Carol, the 590L Gulliver, almost always describe a leveled adaptation with the same title. The notes under the table say which is which.