What is a chapter? The dictionary says it is the main division of a book. That’s true as far as it goes. In nonfiction, it holds a particular subtopic of the work. It’s a logical thing in that case. In fiction, it’s something different. It divides the story line and serves as a way to control the plot. It can also be an entire story in itself, if part of a collection of short stories.
Chapters manipulate the plot by allowing the author to break the action and force the reader to turn a page to continue. Chapters also make it easier to weave in subplots. How many of us have turned a page when we reached the end of an exciting scene to find the author has left the characters in dire straits. The action has moved on to further another character’s part in the story? One minute the villain left the hero locked in a basement with water coming in. Then we turn the page and find ourselves in a coffee shop learning why the villain is doing what he or she is doing. Yes, they are excellent for creating cliff hangers in the plot.
How long should they be? As long as it needs to be to get the point across, well in nonfiction anyway. In fiction, it can be as short as one page and as long as thirty. It’s up to the author. Whatever length serves the plot best is the length it should be. The chapters in a work of fiction control the plot, so no matter many pages and scenes it takes to do that is how long your Chapters should be. Do they all need to be the same length in a book? Of course not. Chapters can and should vary in length. It keeps the reading from becoming monotonous. We don’t want to bore the reader.
The next thing to consider is how many chapters should there be? The answer to that is easy. There should be enough chapters to tell the story with all it’s twists and turns. That could be as few as twelve chapters to thirty-six or longer. Again, it depends on the author and the story he or she wants to tell. A typical cozy mystery or a romance novel have around thirty chapters. Science Fiction, horror and thrillers run longer for the most part. There should be enough chapters in the book to allow the story to reach its conclusion in an easy, logical fashion.
The chapter has an important function in a book, be it fiction or nonfiction. It should hold the information a reader needs to continue to the chapters following in some kind of logical method. Think of them as the milestones on a roadway. They will lead the character to follow the plot and clarifies the action for the reader. So go ahead and let them grow with the story.