The short answer to this one is: it depends. There are different conventions for how long your book should be, based on different genres. Word count can be an important factor in making sure your story is well received by readers (and, as a result, affects sales, reviews, and overall performance).
Word count conventions are not arbitrary, either. There are very good reasons why certain types of books run to a specific length:
- Pacing – Books with a tighter word count will have a faster pace than books with a lengthy word count.
- Worldbuilding – Books that require more exposition in order to situate a reader in an imagined world will be longer than books that are set in a world that readers are already very familiar with.
- Attention – The attention span of your reader is also important to bear in mind. And, it's not just about how long a reader can maintain their attention, but also how much attention they are willing to spend on certain types of books.
Genres where pacing, intrigue, and excitement are important
Readers who are used to fast-paced storytelling may become bored with a longer book if it means that the pace slows down. Certain types of books are intended to move quickly and keep the reader on their toes!
- Horror: 40,000 – 80,000
- Mystery: 40,000 – 90,000
- Western: 45,000 – 75,000
- Memoir: 45,000 – 80,000
- Romance: 50,000 – 90,000
- Thriller: 70,000 – 90,000
Genres where world-building is important
Sci-fi and fantasy fans may be unsatisfied with a shorter novel if it means that the world you've set your story in doesn't make sense to them. They still want great pacing and excitement, but they also need more information in order to feel immersed in the story.
- Dystopian Novel: 60,000 -120,000
- Fantasy Novel: 50,000 – 150,000
- Sci-fi Novel: 50,000 – 150,000
Genres where readers value concise writing
Readers who are looking for specific information value books that are clear, and to the point.
- Self-Help Book: 30,000 – 70,000
Take your audience into account
The ranges above (especially for sci-fi and fantasy novels) are still very broad. So how do you know which end of the spectrum you should be aiming for? Here, you take into account who your audience is and adjust according to that audience's expectations.
- Early reader: 1000+
- First chapter book readers: 5,000 – 20,000
- Middle grade readers: 20,000 – 55,000
- Young adult readers: 60,000 – 90,000
- Adult readers: 60,000+
What about short stories?
There are also word count guidelines for those of us who prefer to be as economical with words as possible.
- Flash fiction: > 1,000
- Short story: > 7,500
- Novelette: 7,500 – 17,500
- Novella: 17,500 – 40,000
The first draft of your book can be longer than any of these word counts! Don't panic if your word count isn't ideal when you're just getting the story on the page. You can always cut it down when you're revising and polishing the story.