Long books, page limits, and splitting into volumes
A long manuscript is a production problem before it is anything else. At Amazon KDP a paperback runs 24 to 828 pages and a hardcover 75 to 550. Those are not guidelines. A file outside the range is refused at upload.
What a long book measures
Spine width is page count times paper bulk, and bulk is a property of the stock. On KDP, white is 0.002252 inches per page and cream is 0.0025.
- 400 pages — white 0.901 in, cream 1.000 in
- 600 pages — white 1.351 in, cream 1.500 in
- 828 pages, the ceiling — white 1.865 in, cream 2.070 in
Note what cream does. At the top of the range it adds 0.205 inches over white on the same manuscript — a fifth of an inch of extra spine bought for nothing but paper color. On a 200-page book that difference is invisible. On a long one it is the difference between a book and a brick.
A 900-page manuscript is not a KDP paperback at all. It is 72 pages past the limit, and had the limit not existed the spine would land near 2.03 inches on white and 2.25 on cream. A perfect-bound block that thick fights being opened. Hardcover is not the escape either: 550 pages is the cap, and KDP's case adds 4.8 mm (0.188976 in) on top of the paper bulk, so a 550-page hardcover is already about 1.43 inches at the spine.
The gutter grows too
The inside margin is not fixed. A thicker book curves harder at the fold, so it needs more paper held back to keep the text readable. The total inside margin goes up in steps with page count: up to 300 pages, 0.5 in; 301–500, 0.625; 501–700, 0.75; 701–828, 0.875.
That means a 700-page book gives up a quarter inch of text width on every page compared with a 300-page one — and less width per line means more lines, which means more pages. Length is mildly self-feeding.
Lever one: tighter typesetting
Smaller type, tighter leading and slightly wider measure all put more words on a page, and on a 700-page book a change that looks trivial removes fifty pages.
The cost is real and it lands on the reader. Below about 10.5 pt in a serif text face the page starts to work against older eyes, and leading pulled too tight makes long stretches of prose feel airless — precisely the wrong thing to do to a reader who has six hundred pages ahead. Use this lever first, but use it by a notch, not by a fist.
Lever two: a larger trim
A bigger page holds more characters per line and more lines per page. Going from 5 × 8 to 6 × 9 is about a third more page area, and the page count falls accordingly.
What you trade is shelf identity. Trim carries genre — a 6 × 9 literary novel and a 5 × 8 one read as different kinds of book before anyone opens them — so this lever is free on nonfiction and expensive on category fiction.
Lever three: paper
White stock is thinner than cream at every printer that offers both. On a long book that is the cheapest inch you will ever find: same words, same layout, a visibly slimmer book. The cost is the page itself, which reads colder and shows a little more show-through.
In the tools. The Interior Formatter reports the real page count for your trim, type size and style, and that count flows straight to the Cover Maker, which computes the spine from it, your paper color, your printer and your binding. Start a book → · about the tools
Lever four: split it
Past a certain length the other three levers are rearranging deck chairs. Two volumes is not a defeat; it is what publishers have always done with long books, and it gives each half a readable block and a sane gutter.
Where to cut. At a structural seam the book already has — the end of a part, a time jump, a change of location or narrator. Never mid-arc to make the halves even. Uneven volumes are normal; a cliffhanger the reader did not agree to is not.
How to number and title them. Put the volume marker where a browsing reader will see it: on the front cover, on the spine, and in the metadata title field on the store. Volume One and Volume Two is clear and dull, which is what you want. A subtitle per volume works well if the parts have names of their own. What does not work is two identical covers distinguished only by a small numeral — readers buy the second one first and blame you.
Each volume is a separate book. Its own ISBN, its own cover file, its own page count and therefore its own spine, its own front and back matter. The front matter of Volume Two should orient a reader who set the first one down three months ago, and the back matter of Volume One should point at the second directly.
There is an upside: each half drops into a lower gutter band. Two 450-page volumes get 0.625 inches of inside margin instead of 0.875, so each page holds more text, and the halves come out a little shorter than half.
Large print hits the wall first
A Large Print edition sets the type at 16 pt on a 6 × 9 page with wider margins, so the same manuscript runs substantially longer. A book that sits comfortably inside the paperback range at normal size can pass 828 pages in large print, which is why large print editions of long novels are so often published in two volumes. Plan the split at the point you decide to make the edition, not at the point the upload is refused.
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: Comics and graphic novels in print · More: How to calculate spine width · Margins and gutters · The large print edition most authors never make