Page count is out of range

The ranges

A paperback needs at least 24 pages. A hardcover needs at least 75. This app caps both at 800. Below the minimum the book is too thin to bind; above the maximum the binding and the spine become unreliable.

The maximum depends on the paper and ink combination as well as the binding, and KDP has adjusted it over time, so treat the cap as a ceiling to stay comfortably under and check KDP's current figure before planning a very long book.

Counting pages correctly

Page count means printed pages, not sheets of paper. Each leaf has two sides and each side is a page, so a 100-leaf book is a 200-page book. The page count of your interior PDF is the number that matters, so count from the exported file rather than from your word processor's status bar.

Blank pages count. A section that starts on a right-hand page leaves a blank left-hand page before it, and front and back matter add more. These are often what pushes a book over a gutter band or under a minimum.

Why the count changes more than the page count

Page count is an input to three other figures: the spine width, the full cover width, and the inside margin. A revision that adds twenty pages can therefore move your gutter into a wider band and widen your spine, which means re-laying the interior and rebuilding the cover. Settle the page count before finishing either file.

When you are under the minimum

Short books — picture books, short guides, some low-content titles — sometimes fall below the paperback minimum. The honest fixes are to add genuinely useful material (notes pages, an index, a glossary) or to publish as an eBook only. Padding with blank pages meets the number but is a poor experience for the reader, and KDP's content guidelines discourage books that are mostly empty.