Jan 21 2010
The shortest, most cheesy answer is “however long it takes to tell the story.” Unfortunately, if it takes you hundreds of thousands of words to tell the story, getting it published it will be practically impossible.
According to Chuck Sambuchino, the most publisher-friendly length for an adult novel manuscript is between 80,000-100,000 words. Science fiction and fantasy authors usually need a bit more space for worldbuilding, so he says the ideal range for them is between 100,000-115,000 words. However, Chuck is sort of working for the Devil, so I’d feel bad if he were my only source for this post.
Colleen Lindsay, a literary agent at FinePrint, has similar guidelines: around 100K for epic fantasy or sci-fi, 80-90K for thrillers and 80-100K for crime fiction. Also, she’s not in league with Lucifer.
Both Chuck and Colleen emphasize that there are exceptions, like first-time novelists publishing 200,000 word behemoths. But such exceptions are extremely rare. If you try going well above or below the usual range, your writing needs to be extraordinary. I would not recommend doing so unless you are absolutely sure that your story cannot work at a more conventional range.
UPDATE: If you’re writing for a younger audience (YA, middle grade, picture books, etc), please see this.