Children’s Books is a broad umbrella term that represents all literature for “younger readers” (ages 2-17), including fiction and nonfiction such as picture books, poetry, chapter books, middle grade books, and young adult books.
The term “children’s books” is often loosely used (or misused) by children’s writers literary agents. For example, an agent might say on her website that she wants “children’s books” when she’s only interested in picture books and chapter books (and not middle grade or young adult books).
Picture Books – A book is for children ages 2-9
*contains a significant amount of artwork
*the story may be told partially (or entirely) in pictures
*most picture books have 1,000 words or less
*can be fiction (about fake things) or nonfiction (real/true – biographies, etc.)
Juvenile – another broad umbrella term that includes two subgenres or subcategories: chapter books and middle grade books.
– Chapter Books – fiction and/or nonfiction books are for “intermediate readers,”
* usually ages 7-10, and they’re usually between 2-10,000 words
*chapter books often contain many illustrations
*they consist primarily of prose
*usually divided into short chapters.
– Middle Grade – is for readers ages 8-12
*word count for a middle grade book is 20-40,000 words
* Middle grade books can be fiction and/or nonfiction.
– Young Adult – is for readers age 12-17.
*Young adult books can be fiction and/or nonfiction
* They are 50-60,000 words
* subgenres such as: mystery, romance, adventure, career, success, etc.
Here is additional information taken from Literary Rambles
– Board Books: 0 – 100 words.
– Early Picture Books: 0 – 500 words.
– Picture Books: 50 – 1,000 words. 1k is pushing it.
-Nonfiction Picture Books: 500 – 2,000 words.
-Early Readers: 200 – 3,500 words, depending on age level.
– Chapter Books: 4,000 – 10,000 words.
– Hi-Lo Books: 500 – 50,000 words, varies greatly depending on age level. A large number fall between 500 – 20k words. Some 60-90k YA books get classified as Hi-Lo, but I don’t think they were specifically written for the category.
– Middle Grade: 25,000 – 45,000 words, usually around 35-40k. Longer word counts allowed for fantasy, sci-fi, historical. Up to 60-70k is probably safe (though there are even longer exceptions).
– Young Adult: 45,000 – 70,000 words. Longer word counts allowed for fantasy, sci-fi, paranormal, historical. 80-90k is safe (there are some as high as 120k, but I recommend staying below 100k, if possible).
– Nonfiction MG/YA: 5,000 – 70,000 words, varies greatly (with some exceeding 100k) depending on the type of book and age level (I recommend researching similar titles to what you’re writing/proposing to find appropriate range). Memoirs seem to fall within the same range as novels for their age group.