Amazon KDP Trim Sizes and Margins Guide (2026)

Published July 27, 2026 · 11 min read

Trim size shapes how a print book feels, how many pages it needs, and what it costs to manufacture. Margins determine whether the finished pages are comfortable to read. Choose these settings after the manuscript is stable but before final typesetting, because changing them later reflows the entire book.

This guide uses Amazon's official trim size, bleed, and margin requirements and paperback submission guidelines, reviewed July 27, 2026. KDP can change supported combinations and page limits, so confirm your exact format in the Bookshelf before ordering a proof.

If the draft is still changing, finish the book first. ShakespeareAI's AI book writer helps authors plan, draft, and revise chapters before production decisions lock the page layout.

What trim size means on Amazon KDP

Trim size is the final width and height of a printed page after manufacturing. It is not the size of the complete cover and, when an interior has bleed, it is not the size of the uploaded PDF page. KDP identifies 6 × 9 inches (152.4 × 228.6 mm) as the most common U.S. paperback trim size.

A larger page usually fits more words, reducing page count, but it can also change the book's proportions, shelf presence, printing tier, and reader experience. KDP treats books wider than 6.12 inches or taller than 9 inches as large trim sizes, which can have different printing costs.

How to choose the right KDP trim size

These are starting points, not genre laws. Measure several professionally published books that serve the same reader. Then test a representative chapter in two sizes at actual scale. Compare line length, pages per chapter, visual density, likely spine width, and KDP's current printing-cost estimate.

Do not choose trim size from word count alone

Word count affects page count, but so do font family, font size, paragraph spacing, line spacing, chapter openings, images, tables, and front matter. A 70,000-word novel and a 70,000-word illustrated guide will not format alike. Use the fully styled manuscript to estimate pages.

KDP bleed vs. no bleed

Bleed means an image, color, or graphic extends beyond the final trim line so it reaches the physical edge after cutting. All KDP covers require bleed. Interior bleed is optional and should be selected only when at least one interior element must touch an edge.

• No bleed: keep all text and artwork inside the safe margins; set the PDF page to the exact trim size.
• With bleed: extend edge-touching artwork 0.125 inch (3.2 mm) beyond the top, bottom, and outside trim edges.
• One bleed page changes the file: if any interior page needs bleed, KDP says the entire interior must be set up as a bleed file.
• PDF is required: KDP supports interior bleed only for fixed-format files such as print-ready PDF.

Bleed page-size formula

For an interior with bleed:

• PDF width = trim width + 0.125 in
• PDF height = trim height + 0.25 in

A 6 × 9 inch book therefore needs a bleed PDF page measuring 6.125 × 9.25 inches. The file must contain individual pages, not two-page reader spreads.

Amazon KDP minimum margin requirements

Every page has an inside margin beside the binding—often called the gutter—and top, bottom, and outside margins. The inside minimum increases as page count rises because a thicker book needs more room near the spine.

The outside values are manufacturing minimums, not necessarily attractive design targets. A novel set at the smallest permitted top, bottom, and outside margins can feel crowded. KDP's Word guide uses a 0.375-inch outside margin for a more professional look and recommends 1-inch top and bottom margins when headers are included. Judge the printed page, not only whether the file passes validation.

Inside margin and software gutter fields

Terminology varies by layout program. Some tools use “inside margin” for the full safe area by the spine; others add a separate gutter value. KDP's general guidance says that if a program presents both inside-margin and gutter fields, use the same required value rather than accidentally shrinking the binding allowance. KDP's step-by-step Microsoft Word instructions instead use mirrored margins and leave Word's separate Gutter field at zero. Follow the workflow for your specific software and verify the resulting distance visually in Print Previewer.

A 6 × 9 novel formatting example

Suppose a text-only paperback finishes at 284 pages after the page size and typography are set:

1. Select a 6 × 9 inch trim size and no bleed.
2. Set the document page size to exactly 6 × 9 inches.
3. Use mirrored pages so left and right inside margins alternate correctly.
4. Because 284 pages falls in the 151–300 range, use an inside margin of at least 0.5 inch.
5. Use at least 0.25 inch for top, bottom, and outside margins, but choose roomier values based on headers, page numbers, line length, and the desired page color.
6. Export embedded fonts to a single-page PDF, upload it, and inspect the complete book.

If the layout grows to 304 pages, the minimum inside margin moves to 0.625 inch. That change can reflow text again, so repeat the page-count and margin check until the settings stabilize.

Step-by-step KDP interior workflow

1. Clean the manuscript. Finish developmental edits, copyediting, front matter, back matter, and major image placement before typesetting.
2. Choose the print specification. Decide format, trim size, ink, paper, bleed, and primary marketplace. Confirm KDP supports that combination and page range.
3. Set page size first. Use the exact trim dimensions for no bleed or the calculated PDF dimensions for bleed.
4. Apply book typography. Set body style, headings, paragraph indents, line spacing, scene breaks, chapter openings, headers, and folios consistently.
5. Check the new page count. Use it to choose the correct inside-margin range. Recheck whenever typography or content changes.
6. Set mirrored margins. Make sure the binding side alternates on left- and right-hand pages.
7. Prepare images. KDP requires interior images to be at least 300 DPI. Extend bleed artwork beyond the trim line while keeping important content safely inside.
8. Export a print PDF. Embed fonts, preserve image quality, output individual pages, and avoid crop marks or printer marks unless KDP explicitly requests them.
9. Use Print Previewer. Review warnings and visually inspect title pages, blank pages, chapter starts, headers, page numbers, images, and the final page.
10. Order a physical proof. Check binding readability, type size, paper show-through, image tone, trim variation, and the book's feel in hand.

Formatting mistakes that cause KDP problems

• Changing trim size after final formatting: this changes line breaks, page count, image position, and often the required gutter.
• Using the draft page count: margins must reflect the final formatted page count, not the manuscript's Word count before resizing.
• Treating minimum margins as ideal design: a technically valid page can still feel cramped or lose content near the binding.
• Uploading spreads: KDP print interiors require individual pages in reading order.
• Selecting bleed without resizing the PDF: a 6 × 9 bleed interior uploaded at 6 × 9 can produce errors or white edges.
• Forgetting that one page controls the file: one edge-to-edge illustration means the entire interior must use the bleed setup.
• Reusing a paperback cover for hardcover: interiors may sometimes be reusable when specifications match, but covers require separate files.
• Skipping the proof copy: a screen cannot reliably show binding loss, paper behavior, physical type size, or trim variation.