Picture books for children up to the age of eight typically have 1000 words (though many are shorter); easy readers for ages five to nine have 50–2500 words (depending on the publisher and level of reader); chapter books (short novels for ages seven to ten) typically have 10,000–12,000 words; and middle grade novels (ages eight to twelve) typically have 10,000–12,000 words. Longer word count books are becoming more common for older readers.
In general, the longer the word count, the more complex the language used and the more mature the content. For example, Young Adult (YA) fiction is usually written with 15,000 words or more as a standard length because that's enough text to contain complicated plots and sophisticated language while still being read by teenagers. In fact, some YA novels are even longer than 20,000 words because writers want their stories to be complete without having to use up all their words.
When choosing a book for your child, it's important to take word count into account. Many families choose books based solely on their genre or author name, which can be problematic because many books fit under more than one category. For example, a picture book for young children may also be considered an easy reader because it uses simple language and illustrations to tell a story. If you select this book then your five-year-old won't get much reading practice beyond basic comprehension skills. A chapter book on the other hand will require more advanced reading skills such as understanding metaphors and using context clues to interpret meaning.
Children ages 8 to 12, or fourth through sixth grades, read sentences of typically 10 words, with a maximum of 20 words. The majority of works created at this level are between 20,000 and 40,000 words long. Children in high school aged 13 to 17, or in the seventh through twelfth grades, read for pleasure and information at the college level, which requires reading more complex material than younger readers.
For most children, the optimal reading level is about grade four. That means that they should be able to understand the main ideas of the text and follow the narrative without too much help from a teacher. Some children, however, remain at a first-grade level for several years after starting school. These young readers need assistance from teachers or parents with more advanced books.
Above a fourth-grade level, there's no harm in reading older material if you enjoy it and your parents let you. But most adolescents don't read at such a high level because it's not necessary for their education. They can get by on less literature than adults because there are other ways to learn about people, events, and issues outside their own time period.
Adults, by contrast, cannot function well without reading at a higher level. That's why we recommend that everyone over the age of eight should be reading at or above a third-grade level.
Children's novels range from 10,000 to 15,000 words, whereas young adult books range from 40,000 to 80,000 words. Thrillers and epic fantasies frequently exceed 100,000 words. Many short and snappy novels are 40,000 to 60,000 words long, yet many nonfiction works are 80,000 words or more. Length is only one factor in determining whether or not a book is suitable for children or adults; others include content, style, and purpose.
In terms of length, it's possible to write a good book that is too short as well as one that is too long. Short stories usually fall between 3,000 and 20,000 words while novellas typically run between 30,000 and 70,000 words. Longer works are common in literary fiction and history. Epics can be hundreds of pages long or more and thrillers may reach 200 pages. However many books fall in between these lengths so there is no right or wrong number per se. It all depends on your writing style and the story you are trying to tell.
The word count of a book is often found at the end of the book along with other information such as awards won by the author and/or illustrator and/or editor. The editor will use this information when deciding how much money to pay the writer and/or artist. Sometimes the publisher will also provide feedback about what length the work should be.