How to Format a Book for Kindle: KDP Formatting Guide

You wrote the book. Now you need to get it into a format that Amazon will actually accept, one that readers will enjoy on their Kindle. This is where most self-publishing authors hit a wall. KDP formatting has specific requirements for eBooks and print books, and getting them wrong means rejected uploads, broken layouts, or a book that looks amateur on the page.

This guide covers exactly what you need to know: accepted file formats, font choices, margins, table of contents setup, front and back matter, image handling, and the most common mistakes that trip people up. The standards apply to novels and nonfiction guides alike.

KDP-Accepted File Formats

Amazon KDP accepts different file formats for eBooks and paperbacks. The format you choose matters more than most authors realize.

For eBooks (Kindle)

EPUB is the preferred format. KDP converts EPUB files into their proprietary Kindle format (KPF) on upload. EPUB gives you the most control over how your eBook renders across devices.
DOCX is Microsoft Word format. KDP accepts DOCX and converts it internally. This is the easiest option if you wrote your book in Word or Google Docs, but you have less control over the final rendering. Use clean, simple formatting: no text boxes, no columns, no manual page breaks for layout.
KPF stands for Kindle Package Format, created with Amazon's Kindle Create tool. Good for fixed-layout books like cookbooks or children's books. Overkill for most fiction and standard nonfiction.

For Print (Paperback and Hardcover)

PDF is the only accepted format for print interiors. Your PDF must be print-ready: correct trim size, embedded fonts, proper margins, and no crop marks unless required. KDP will flag issues during the upload review.
DOCX also works for print, but KDP converts it to PDF internally. You lose control over page breaks, widows/orphans, and precise layout. For professional results, export your own PDF.

Bottom line: Use EPUB for eBooks and PDF for print. DOCX works as a fallback, but you're handing control to Amazon's converter, and the results can be unpredictable.

eBook Formatting: Reflowable Text

Kindle eBooks use reflowable text. This is the single most important concept to understand before you start formatting. Unlike a printed page, an eBook has no fixed page size. The text reflows to fit whatever device the reader is using: a Kindle Paperwhite, an iPhone, a tablet, a desktop app.

This means several things for your formatting:

No fixed page dimensions. Don't set a page size in your eBook manuscript. There is no “page,” only a continuous flow of text that the device breaks into screens.
No hard page numbers. Page numbers are meaningless in a reflowable eBook because the “page” depends on font size, screen size, and orientation. KDP generates location numbers instead.
No headers or footers. The Kindle app controls what appears at the top and bottom of the screen. Your manuscript should not include running headers, footers, or page numbers.
Font embedding is optional. Readers can override your font choice on their device. You can embed fonts in EPUB, but there's no guarantee they'll be used. Focus on a clean structure rather than specific typefaces.

Print Formatting: Trim Size, Margins, and Bleed

Print books are fixed-layout. Every page is exactly the size you specify, and the formatting needs to account for physical printing and binding.

Trim Size

The standard KDP trim size for most books is 6" x 9". This works for fiction, nonfiction, memoirs, and most genres. Other common options:

5" x 8" is slightly smaller, common for novels and poetry
5.5" x 8.5" is a middle-ground option
8.5" x 11" is large format, suited for workbooks, textbooks, and image-heavy nonfiction

Pick your trim size before you start formatting. Changing it later means reflowing the entire interior and redoing your cover.

Margins

KDP has minimum margin requirements that vary by page count and trim size. The critical one most authors miss is the gutter margin, the inside margin along the spine where pages are bound together. A book with 300+ pages needs a larger gutter than one with 100 pages, because the thicker spine pulls the inside text toward the binding.

For a 6" x 9" book with 150–400 pages:

Inside (gutter) margin: at least 0.75"
Outside margin: at least 0.5"
Top and bottom margins: at least 0.5"

Add more if the content feels cramped. Readers notice tight margins even if they can't articulate why a book feels unpleasant to read.

Bleed

If your book has images, color backgrounds, or any content that extends to the edge of the page, you need bleed. That means an extra 0.125" of content beyond the trim line on all three outer edges. If your book is text-only, you don't need bleed and can disable it during KDP setup.

Font Choices

For print books, Georgia at 12pt is the standard for body text. It's a serif font designed for readability on both screens and paper, and it's what most traditionally published books use in similar digital-first workflows. Other solid choices:

Garamond is a classic book font, slightly more compact than Georgia
Palatino reads cleanly, slightly wider than Georgia
Times New Roman is functional but feels more like a school paper than a published book

For eBooks, the font matters less because readers can change it. But setting a sensible default (Georgia, Bookerly, or a similar serif) gives your book a professional starting point.

Use a larger, bolder font for chapter titles. 18–24pt for chapter headings works well in print. Keep subheadings at 14–16pt. Consistent sizes throughout the book matter. Inconsistency is the fastest way to make a self-published book look self-published.

Chapter Headings and Page Breaks

Every chapter must start on a new page. In both eBook and print formatting, insert a page break before each chapter heading. Not blank lines, not manual spacing. A proper page break.

For eBooks:

Use the page break feature in your editor (not pressing Enter twenty times)
Mark chapter titles as Heading 1 in your document structure
KDP uses Heading 1 tags to build the navigational table of contents

For print:

Chapters traditionally start on a recto (right-hand, odd-numbered) page. This means you may need a blank page before some chapters. KDP allows you to set this in your PDF.
Drop the chapter title about one-third of the way down the page for a professional look

eBooks and print books handle the table of contents differently, and you need both if you're publishing in both formats.

eBook: Navigational TOC

Kindle requires a navigational table of contents built into the file structure. This is the TOC that appears when readers tap the menu icon. It's generated from your heading structure (Heading 1 tags in DOCX, or the TOC metadata in EPUB). This is not a page in your book. It's a structural component of the file.

You can also include an inline TOC (an actual page with clickable chapter links), but the navigational TOC is what Amazon requires and what most readers use.

Print: Printed TOC

Print books need a traditional table of contents page listing chapter titles and page numbers. This goes in the front matter, after the copyright page and before the first chapter. Page numbers must match the actual printed pages, so finalize your TOC last, after all other formatting is complete.

Front Matter Formatting

Front matter is everything before Chapter 1. The standard order:

Half title page. Just the book title, centered, no subtitle or author name. Optional but professional.
Title page. Full title, subtitle, and author name. Centered on the page.
Copyright page. Copyright notice, year, ISBN (if applicable), publisher info, “All rights reserved” statement, edition information.
Dedication. Optional. Keep it short. One page.
Table of contents. Required for nonfiction, recommended for fiction with named chapters.

For eBooks, front matter should be minimal. Readers want to start reading quickly, and Amazon's “Look Inside” preview starts from the beginning of your file. If the first five screens are front matter, potential buyers never see your actual writing.

Back Matter Formatting

Back matter goes after the final chapter and before the end of the file. Use it to build your author platform:

About the Author. Two to three paragraphs, written in third person. Include a call to action (website, newsletter signup, social media).
Also By. List your other books with titles. In eBooks, make these clickable links to their Amazon pages.
Acknowledgments. Optional. Placed here rather than in front matter to keep the book start clean.
Bibliography or Resources. For nonfiction books that reference external sources.

In eBooks, back matter is where Amazon places the “Before you go” prompt asking readers to leave a review. Make sure your back matter doesn't interfere with that placement.

Images in eBooks vs. Print

Images work differently in eBooks and print.

eBook Images

Maximum file size per image: 5 MB. Total eBook file size should stay under 650 MB but aim for well under that.
Use JPEG for photographs and PNG for graphics, diagrams, or anything with text.
Resolution: 300 DPI at the intended display size. Kindle will downscale for smaller screens, but starting high ensures quality on tablets.
Images reflow with text, so never rely on precise image-to-text positioning. Use captions if context is needed.

Print Images

Resolution must be at least 300 DPI at actual print size. A 72 DPI web image will look blurry and pixelated in print.
Color images require a color interior (higher printing cost per page). If your book is black-and-white, convert all images to grayscale before export.
If images touch the page edge, you need bleed enabled (0.125" extra on outer edges).

Common Formatting Mistakes

These errors cause the most rejected uploads, broken layouts, and frustrated readers:

Hard page numbers in eBooks. Kindle assigns its own location numbers. Including manual page numbers creates duplicate or nonsensical numbering.
Headers and footers in eBooks. The Kindle app renders its own header and footer bars. Your headers will appear as in-body text, repeated on every screen.
Oversized images. A 10 MB image slows download times and can push your eBook over the delivery cost threshold, eating into your royalties.
Inconsistent spacing. Mixing single-spaced and double-spaced paragraphs, or using manual line breaks instead of paragraph spacing, creates a ragged, unprofessional layout.
Using tabs for indentation. Tabs render differently across devices. Use first-line indent settings in your paragraph styles instead.
Forgetting the gutter margin. Text disappearing into the spine is the number one complaint from print-on-demand readers.
No navigational TOC. Amazon will reject your eBook if it doesn't include a navigational table of contents in the file structure.
Font licensing issues. If you embed a font in your EPUB or PDF, make sure you have a license for embedding. System fonts like Georgia and Garamond are safe.

The DOCX Approach vs. the EPUB Approach

Most self-publishing authors face a choice: format in Word (DOCX) and let KDP convert, or build a proper EPUB file.

DOCX (Simpler, Less Control)

Write in Word or Google Docs. Use built-in heading styles (Heading 1 for chapters, Heading 2 for sections). Insert page breaks between chapters. Upload the DOCX directly to KDP and preview the result.

This works for straightforward text-only books. The trade-off is that you're relying on Amazon's converter, which sometimes makes odd spacing or font decisions. Always preview before publishing.

EPUB (More Work, Full Control)

Use a tool like Sigil, Calibre, or Vellum to build an EPUB file. This gives you control over every aspect: CSS styling, font embedding, image placement, metadata, and the navigational TOC structure. EPUB is the standard for professional eBook production.

The downside is the learning curve. Building a clean EPUB from scratch requires understanding basic HTML and CSS, or using dedicated formatting software.

How BookSmith Handles Formatting Automatically

Formatting specifications and file conversion are a lot of work. That's why BookSmith exists.

When you create a book with BookSmith, the platform generates all of your publishing files automatically:

EPUB with proper navigational TOC, clean reflowable text, and correct metadata
DOCX formatted with Georgia 12pt, proper heading styles, and a generated table of contents
Print-ready PDF at 6" x 9" with correct gutter margins, page breaks, recto chapter starts, and embedded fonts
Front matter including title page, copyright page, dedication, and table of contents, formatted to KDP standards
Back matter including about the author section and “also by” page, ready for your details
Cover files — JPEG at 1600x2560 for eBook, plus print-ready PDF covers with spine width calculated from your page count

You write. BookSmith formats. Every file is KDP-ready out of the box, with no manual conversion, no margin math, and no fighting with Word styles. If you want to see how the full publishing process works, check out our complete guide to self-publishing on Amazon KDP, or read our KDP publishing guide for a step-by-step walkthrough.