Book Format Sizes: A Side-by-Side Guide to Print, Ebook, and Audiobook

The word "format" means something different in every medium. In print, format is a physical dimension — the trim size of the bound book. In ebooks, format is largely irrelevant as a dimension because the reader controls the text size and the device controls the layout. In audiobooks, format does not exist at all as a spatial concept — runtime and chapter structure take its place.

Authors planning a multi-format release often try to carry print decisions into digital formats. That thinking produces unnecessary complexity in ebooks and confusion about what audiobook production actually involves. This guide clarifies what "size" and "format" mean in each medium, where the concepts overlap, and how to plan your formatting work when you are producing all three versions of the same book.

Print Format Sizes

Print is the only medium where physical dimensions are a literal specification that affects production.

The standard trade paperback sizes used by most indie authors are 5.5 × 8.5 inches and 6 × 9 inches. The 6×9 size is the most common for US trade paperbacks — novels, memoirs, narrative nonfiction, and business books. The 5.5×8.5 is slightly smaller and suits shorter books, literary fiction, and authors who want a less imposing physical presence on the shelf.

For large-format nonfiction — textbooks, workbooks, technical guides, illustrated content — 7 × 10 inches and 8.5 × 11 inches are standard. For mass-market fiction targeting airport and drugstore distribution, 5 × 8 or the mass-market-specific 5.06 × 7.81 are used, though these are less common for indie authors since the distribution channels that serve those sizes require significant volume.

Trim Size	Common Use	Platforms
5 × 8 in	Short fiction, poetry	KDP, IngramSpark
5.5 × 8.5 in	Fiction, memoir, shorter nonfiction	KDP, IngramSpark, Lulu
6 × 9 in	Trade nonfiction, novels	KDP, IngramSpark, Lulu
7 × 10 in	Textbooks, workbooks	KDP, IngramSpark, Lulu
8.5 × 11 in	Workbooks, activity books	KDP, IngramSpark, Lulu

The choice of trim size affects page count, printing cost, and spine width. See book trim sizes guide for the full analysis of trim size selection.

Ebook Format: Why Dimensions Do Not Apply

Ebooks are almost universally distributed as EPUB files (or the Kindle-specific MOBI/KFX formats that Amazon derives from EPUB). The fundamental property of a standard ebook is that it is reflowable: there is no fixed page, no fixed line length, and no fixed font size. The reader sets the font size, and the text reflows to fill whatever screen dimensions the device has.

This means the concept of "page size" does not exist in a meaningful way for standard ebooks. A reader using a Kindle Paperwhite in large-print mode will have far fewer words per "screen" than someone using a tablet in landscape mode with a small font. The text adjusts dynamically.

What does matter in ebooks:

Typography choices in the source file. The fonts, heading styles, and spacing you define in your EPUB stylesheet influence how the book looks across devices, within the limits of what each reader app will override.

Chapter breaks and structural navigation. The EPUB table of contents is generated from heading tags in your file. Proper chapter breaks allow readers to navigate and device apps to show reading progress accurately.

Image handling. Images in ebooks should be optimized for screen — typically JPEG or PNG at 72 to 150 dpi for inline images, with a width that works across small phone screens and large tablet displays. Images that are enormous in pixel dimensions inflate file size without improving reading quality on most devices.

Metadata. Title, author name, ISBN, language, and subject categories are embedded in the EPUB file itself. Clean metadata affects how the book appears in storefronts and library systems.

Front matter and back matter. Ebooks should not start reading position at the title page. Most platforms let you specify where the book starts (the "start reading" position), which should be the first chapter page, not the copyright page.

What does not matter: the exact pixel dimensions of the "page." The reader's device controls this.

Fixed-Layout Ebooks: When Ebooks Do Have a Size

There is an exception: fixed-layout EPUB. A fixed-layout ebook preserves an exact visual layout — each "page" is a defined canvas size, and content does not reflow. This format is used when the visual relationship between text and images must be preserved precisely.

Common use cases:

• Children's picture books, where text is positioned over illustrations on specific pages
• Cookbooks with complex layouts where ingredients and instructions are visually paired
• Art books and photography books where image placement is integral to meaning
• Graphic novels

Fixed-layout EPUBs define a canvas size in the EPUB manifest. The standard canvas sizes used by major publishers are:

• 1200 × 1600 pixels — Common for portrait-oriented picture books (approximates a 6×8 page at 200 dpi)
• 2048 × 1536 pixels — iPad landscape (used for some interactive or landscape-format children's books)
• 1800 × 2400 pixels — Higher-resolution portrait (used for print-quality reproduction of illustrated content)

These pixel dimensions are the closest equivalent to "size" in ebooks, but they function as design canvas dimensions, not physical trim sizes. A fixed-layout ebook designed at 1200 × 1600 pixels will display at different physical sizes on different devices — an iPhone screen, a large iPad, and a Fire HD all show the layout at different physical scales.

Fixed-layout EPUBs are significantly more complex to produce than standard reflowable EPUBs. They require either specialized software (Adobe InDesign with the EPUB export pipeline, or purpose-built children's book tools) or manual EPUB construction. They also have uneven support across reading platforms — Amazon's KFX format handles them differently than Apple Books, and some smaller ebook retailers have limited fixed-layout support.

Audiobook: No Size, but Structure Still Matters

Audiobooks have no spatial dimensions at all. The analogous concerns are runtime and chapter structure.

Runtime is the audiobook equivalent of page count. Most commercial audiobooks run between 6 and 15 hours. A standard-length novel (80,000–100,000 words) typically produces 8 to 10 hours of audio at a professional narrator's pace of roughly 9,000 to 10,000 words per hour.

Runtime affects:

• Production cost if you are hiring a narrator (ACX and Findaway Voices both calculate narrator fees per finished hour)
• Listener pricing expectations (most listeners expect full-length audiobooks in the 8–12 hour range for standard retail pricing)
• Royalty structures on platforms that pay per hour consumed (Audible's Plus Catalog model pays based on hours listened)

Chapter structure in an audiobook determines how chapters are labeled in the audio file metadata and how they appear in the chapter navigation of audiobook apps. Each chapter should be a separate audio file (usually MP3 at 192 kbps CBR stereo, per ACX specifications) or a marked chapter break in a single continuous file, depending on the platform's submission requirements.

Unlike print and ebook, audiobook production requires a fundamentally different deliverable — recorded audio, not a formatted document. The manuscript is the source, but the production workflow diverges completely.

Planning Across All Three Formats from the Same Manuscript

The most efficient approach is to treat the manuscript as the single source of truth and produce each format's output from it independently, rather than converting one format into another.

The anti-pattern to avoid: Formatting a print PDF, then trying to convert it back into an ebook. Print PDFs are not designed for conversion. They embed fonts, use absolute positioning, and represent text as static layout — all of which create messy output when converted to reflowable EPUB. The print PDF and the EPUB should both originate from the manuscript, not from each other.

A rational multi-format workflow:

1. Complete the manuscript in a word processor (Word, Scrivener, Google Docs)
2. Export or format a clean EPUB from the manuscript source, with proper heading styles and chapter structure
3. Format a print interior PDF separately, applying trim-size margins, running heads, and page numbers
4. Distribute the EPUB to ebook platforms and the PDF to print platforms
5. For audiobook, produce audio from the manuscript source independently (or hire a narrator who works from the same document)

The ebook and print versions share content but not layout. That is normal and correct. They are different products for different reading experiences.

Formatting Decisions That Affect Multiple Formats

Some manuscript-level choices have downstream effects across all three formats and should be made deliberately.

Chapter headings. In print, chapter headings are styled visually — font size, spacing, small caps. In ebooks, chapter headings must be marked with proper heading tags (H1 or H2) to generate the table of contents. In audiobook production, chapter headings tell the narrator where chapter markers go. A manuscript that uses consistent, clearly marked chapter headings is easier to format across all three media.

Images and figures. Images that are integral to a print nonfiction book (diagrams, charts, photographs) require separate handling in ebooks (optimized for screen, with alt text) and cannot appear in audiobooks at all. If your book is heavily visual, plan for how visual information will be described or conveyed in the audio version.

Footnotes and endnotes. Print handles footnotes at the bottom of the page. EPUBs convert footnotes to pop-up notes or endnotes linked via hypertext. Audiobooks either skip footnotes, read them in-line, or read them as a block at the end of each chapter. Decide your approach before formatting and keep it consistent.

Front matter. Print front matter (half title, full title, copyright, dedication, table of contents) is expected in print and ebook but should not bloat the audiobook opening. Professional audiobooks include a brief copyright notice and then go directly to the content.

Drop caps and ornamental typography. These work well in print, require special CSS handling in ebooks (with inconsistent rendering across reading apps), and are irrelevant to audio. Do not build your book's identity around typographic effects that cannot survive format translation.

File Formats by Medium

Each medium has a correct file format for distribution:

Medium	Primary Format	Notes
Print	PDF	PDF/X-1a preferred for professional print; standard PDF acceptable for KDP and IngramSpark
Ebook (Amazon)	EPUB (converted to KFX)	Amazon accepts EPUB and converts it; also accepts DOCX for simpler books
Ebook (all others)	EPUB	EPUB 3.0 standard; EPUB 2 still accepted at most platforms
Audiobook	MP3	192 kbps CBR stereo per ACX specs; some platforms accept WAV for mastering

MOBI format, previously required by Amazon, is deprecated. Amazon's publishing tools now accept EPUB directly and perform the KFX conversion internally.

PDF should not be submitted to ebook platforms as the primary ebook file. Some platforms (Smashwords/Draft2Digital) can process DOCX, but EPUB gives you more control over the output.

See epub formatting best practices for detailed guidance on EPUB structure, metadata, and stylesheet best practices.

What Changes When You Go from Print to Ebook

Converting a well-formatted print book to a well-formatted ebook requires several deliberate changes — it is not a mechanical conversion:

Remove running heads and page numbers. These are print conventions. EPUBs do not have running heads, and page numbers in an ebook are non-sensical because there are no fixed pages.

Remove print-specific spacing. Widow/orphan control, manual page breaks to position chapter openers on right-hand pages, and hard line breaks for visual effect all behave unpredictably or incorrectly in reflowable EPUB.

Convert footnotes. Footnotes placed at the bottom of a print page need to be converted to EPUB popup notes or endnotes with bidirectional hyperlinks.

Adjust image resolution. Images at 300 dpi for print are unnecessarily large in ebooks and inflate file size. Screen-optimized images at 72–150 dpi are appropriate.

Add hyperlinks where applicable. Ebooks can include clickable links. Nonfiction books with references to websites or other books benefit from live hyperlinks that do not exist in print.

Set the reading start position. Specify where the ebook opens by default — this should be the first chapter, not the title page.

Verify table formatting. Complex tables that work in print may be unreadable in a reflowable ebook at small screen sizes. Consider simplifying or replacing them with text descriptions for the ebook version.

Format Comparison: Print vs. Ebook vs. Audiobook

Dimension	Print	Ebook	Audiobook
Physical size	Fixed (trim size)	N/A (reflowable)	N/A
Page count	Fixed	Dynamic (device-dependent)	N/A
Runtime equivalent	N/A	N/A	Hours of audio
Primary file format	PDF	EPUB	MP3
Typography control	Full	Partial (reader can override)	N/A
Images	Full support	Supported, needs optimization	Not applicable
Navigation	Table of contents, page numbers	Hyperlinked TOC, chapter markers	Chapter markers in metadata
Font control	Full	Limited (reader app may override)	N/A
Production complexity	Medium	Low to medium	High
Distribution cost	Per-unit printing cost	No printing cost	Production cost only

Frequently Asked Questions

Does my ebook need to be the same "size" as my print book? No. The concept of size does not apply to reflowable ebooks. Your ebook is formatted independently from your print interior. They share content but not layout.

If I change my print trim size, do I need to redo my ebook? No. The ebook is unaffected by print trim size changes. You only need to update your print interior PDF and cover file.

What is the difference between a reflowable ebook and a fixed-layout ebook? A reflowable ebook adjusts its layout dynamically based on the reader's font size and device. A fixed-layout ebook preserves an exact visual design on every "page." Fixed-layout is used for picture books and illustrated books; reflowable is used for text-based books.

Can I use the same cover image for print, ebook, and audiobook? The cover image source artwork can be the same, but the file specifications differ. Print covers require a high-resolution PDF with bleed (300 dpi). Ebook covers are submitted as a JPEG (minimum 1600 × 2560 pixels). Audiobook covers require a square JPEG (minimum 2400 × 2400 pixels). You will need to crop or adjust the design for audiobook use since standard book covers are portrait-oriented.

Does an audiobook need a separate ISBN? Yes. Each format — print, ebook, audiobook — requires its own ISBN for proper retail identification. If you are distributing through ACX, they provide a free ASIN for Amazon distribution, but you will need a separate ISBN if distributing the audiobook through Findaway Voices to other retailers.

LiberScript formats your manuscript for print and ebook simultaneously — one workflow, correct output for both. Get started with a Day pass to format your manuscript today.