Frequently asked questions
Short, citable answers to the questions we get most. Each one links to a dedicated page with the full breakdown.
How much does it cost to format a book?
Typical costs in 2026: human formatters charge $50–200 per book (more for complex layouts); desktop software costs $147 (Atticus) to $249 (Vellum) one-time; browser tools like Ceeryo charge per book at a fraction of a human formatter. Free options (Reedsy Studio, Kindle Create) produce standardized interiors with limited design.
What page size (trim) should my book be?
6×9 in is the standard for novels over ~60,000 words and most nonfiction — more words per page, lower print cost per copy. 5×8 or 5.25×8 suit shorter fiction and novellas; 5.5×8.5 is a comfortable middle. Match your genre's shelf and, for a series, match your earlier books.
Why did KDP reject my interior PDF?
The four usual reasons: the PDF's page size doesn't exactly match your chosen trim; fonts aren't embedded; the inside margin (gutter) is below KDP's minimum for your page count; or the page count is outside 24–828. Word exports commonly fail the first two.
Can I format a book in Microsoft Word?
You can, but it fights you: Word can't do mirrored gutters that grow with page count, recto-only chapter openers, suppressed running heads on openers, or reliable font embedding in exported PDFs. Authors who try usually spend days and still fail KDP preflight. Write in Word; typeset elsewhere.
How long does book formatting take?
Automated typesetting: about a minute — a full-length novel typesets in under 60 seconds with Ceeryo. Human formatters: typically 1–3 weeks including revision rounds. Doing it yourself in Word: most authors report days of fighting page breaks and margins.
What file formats does KDP accept?
For paperback interiors KDP recommends PDF (print-ready, fonts embedded); it also accepts Word documents but converts them with less predictable results. For ebooks KDP accepts EPUB and Word files, converting them to Kindle format on upload.
Do I need to buy an ISBN to publish on KDP?
No — KDP assigns a free ISBN to paperbacks (ebooks don't need one on Amazon at all). Buying your own ISBN matters only if you want to be listed as the publisher of record or plan to distribute the same edition beyond Amazon.
What makes a PDF 'print-ready' for KDP?
Four things, all checkable: every page sized exactly to your trim; all fonts embedded in the file; the inside (gutter) margin meeting KDP's minimum for your page count; and the page count inside KDP's 24–828 range. 'Looks fine on my screen' is none of these.