Changing your page count on purpose
Authors talk about page count as though it were a property of the manuscript, like word count. It is not. Word count is fixed; page count is what happens when you pour those words into a trim size at a type size with a set of margins. Change any of those and the number moves.
That is useful, because the number sometimes has to land somewhere specific.
Reasons to move it
You are over a ceiling. Each printer has a maximum. KDP paperbacks run 24 to 828 pages and hardcovers 75 to 550, so a long book can simply be too thick to print as one volume in a given binding. Getting under the line beats splitting the book in two.
You are under 80 pages. KDP prints text on the spine only above 79 pages. Below that the spine is blank — no title, no author, nothing for a bookshelf. A short book that lands at 74 pages is worth pushing to 80.
You want the book cheaper to print. Print cost rises with page count everywhere, and on a print-on-demand title it comes out of your margin on every copy sold. Twenty pages is not nothing.
The end of the book is a mess. The last chapter finishes on a left-hand page and the back matter leaves three or four blank leaves before the book stops. Moving the count slightly usually fixes it.
The levers, ranked
Ranked by how much they move the count — but read the second half of each one, because the cheapest lever in pages is often the most expensive to the reader.
Type size and leading. By far the biggest effect. Dropping 11 point type to 10.5, or tightening leading by half a point, can take twenty or thirty pages off a novel. It is also the change a reader feels most directly, because it is a change to the thing they are looking at. See Type size, leading and the line that reads well.
Trim size. A 6 × 9 page holds meaningfully more text than a 5 × 8 one at the same settings, so moving up a trim can cut a long book's page count by a fifth or more. The cost is that trim is a genre signal — readers expect a mass-market novel and a business book to be different shapes — and changing it means rebuilding the cover. Settle this one early. See Choosing a trim size.
Margins. Narrowing the outside and foot margins adds lines per page. The inside margin is not available in the same way: the gutter is a floor set by the page count, not a preference. Up to 300 pages it is 0.5 inch, 301 to 500 pages 0.625, 501 to 700 pages 0.75, and 701 to 828 pages 0.875. Those grow because a thicker book curves harder at the spine, and going under them buries the last word of every line in the binding. See Margins and gutters.
Indents and paragraph spacing. If your paragraphs are separated by blank space as well as indented — the manuscript habit — removing the space can shorten a dialogue-heavy novel substantially, and it is also the correct setting for a trade book. This is the rare lever that makes the book both shorter and better. See Indents, spacing, and how paragraphs should start.
Whether chapters start on a right-hand page. Traditional books open each chapter on a recto, the right-hand page, which means a chapter ending on a recto is followed by a blank verso. Across thirty chapters that averages roughly fifteen blank pages. Letting chapters start on either page recovers them, at the cost of a slightly less formal book. Fiction often does; nonfiction rarely.
Front and back matter. Every page you add in front or behind is a page. A three-page acknowledgment section and a two-page author bio cost five. They may earn their place — back matter is where your next sale is — but count them deliberately rather than discovering them. See What goes in the front of a book, and in what order and The back of the book is where your next sale is.
In the Interior Formatter. Every setting recomposes the whole book and reports the real page count, so you can see what a half point of leading or a different trim actually costs before you commit to it — and the final count flows to the Cover Maker. Start a book → · about the Interior Formatter
Paper changes thickness, not page count
This catches people. Switching from white paper to cream does not change how many pages the book has — it changes how thick those pages are. At KDP, white bulks at 0.002252 inch per page and cream at 0.0025, so 300 pages is about 0.676 inch of white and 0.75 inch of cream.
That is a spine decision, not a length decision. If you are trying to make a thin book feel more substantial on a shelf, cream is a lever. If you are trying to get under a page ceiling, it does nothing at all. See White or cream paper?.
The trap
The obvious move when a book is a few pages too long is to shrink the type a little and tighten the leading a little. Resist it.
A book set too small and too tight reads cheap, and the tell is that readers cannot name what is wrong. They report that it was tiring, or dense, or that it felt self-published, and they put it down sooner. You saved a few pages and paid for them in the only currency that matters.
Work in this order: paragraph spacing, then chapter starts, then the matter you actually need, then the trim. Touch size and leading last, and only within a range that still reads well on a printed spread. If the book will not fit its binding without going under that range, the honest answer is a different trim, a different binding, or two volumes.
The spine follows the interior
Once the count settles, it flows to the Cover Maker and the spine is computed from it, with your paper color and printer. Which is the real reason to finish the interior first: every page count you try is a different cover. See How to calculate spine width.
Make yours
Everything here is built into the tools, and they are free to use: name your book, bring your manuscript or your artwork, and work as long as you like. You only pay when you want the files without the preview watermark.
Next: Margins and gutters · More: Type size, leading and the line that reads well · Parts, sections and the pages between chapters · How to calculate spine width