How Long Should My Book Be?

An important part of the equation of any book should be its length.  The simple and not so inaccurate answer is however long it needs to be.  I'm a big believer in stories going as long as they're entertaining and/or interesting.  I think that when people try to artificially lengthen or shrink a story, they damage it.  In fact, I wish movies would switch to a more open format, charging viewers based on their lengths.  There are some movies that would be wonderful 30 minute stories but feel stretched into two hours, (I felt that way when I saw Ex Machina,) while some movies are true epics and should last 3 or 4 hours, or be series.  (I felt that way when I saw the movie Elizabeth.)

However, you do want to make sure to categorize your book accordingly, then price and promote it based on its length.  If a story is more of a novella, you don't want people expecting an epic and being let down.  That only leads to bad reviews.  Likewise, if your story is a simple one, and it drags on, people aren't going to finish it.

Having come from the film industry, my own rule of thumb on novels comes from comparing the number of minutes to the number of words.  A typical movie is a little over or under 100 minutes, (about 70 minutes to 130 minutes.)  A typical novel is a little over or under 100,000 words, (about 70,000 to 130,000 words.)  That's average.  If you have a specific promotional goal in mind that you plan to sell it like it's Game of Thrones, you go for more words.  If you're going for a more serialized view where you're coming out with a lot of books, you go for fewer.  But be careful how few you go, you don't want the readers feeling it's more of a short story.

There are things you can do with sizes of pages and typsetting with the physical books, but remember that most people are purchasing your books on Kindle, so word count is more important than ever today.

10,000 - 30,000 words usually makes a short story, and 30,000 to 70,000 is usually a novella, but these numbers are flexible.  The most important thing to bear in mind is what your readers will be interested in, and be honest with them, because the most important thing to remember is that reviews trump everything in the book world.  They not only cause people to decide whether or not they'll buy your book, but they also place you up or down the rankings on sites like Amazon.