KDP Margin Requirements: How to Set Up Your Paperback Correctly

KDP Margin Requirements by Page Count

The inside margin grows as the book becomes thicker. More pages create a wider spine and a deeper binding area, so text needs more room to remain comfortably visible.

The outside, top, and bottom minimums are determined primarily by bleed: 0.25" (6.4 mm) without bleed or 0.375" (9.6 mm) with bleed. The official table uses 9.6, 12.7, 15.9, 19.1, and 22.3 mm for the five inside-margin tiers.

Use the page count from the completed interior PDF, including front matter and intentional blank pages. A particular trim, ink, and paper combination may have a lower maximum page count than 828.

What Are Inside and Outside Margins?

The inside margin is the edge nearest the spine and binding. The outside margin is the outer edge of the page. On facing pages, those positions mirror one another: the inside edge is on the right of a left-hand page and on the left of a right-hand page.

Top and Bottom Margins

Top and bottom margins protect headers, page numbers, chapter text, and body content from the trim area. KDP currently requires the same minimum at the top and bottom as at the outside edge.

The minimum is not necessarily the most attractive layout. Larger top and bottom margins can provide room for headers, page numbers, spacious chapter openings, and a calmer page design.

Inside Margin vs. Gutter

Amazon commonly uses inside margin and gutter to describe the binding-side space, but layout programs do not all implement those terms in the same way. Avoid copying one software instruction into another program without checking how it calculates the final inside space.

In Microsoft Word, Amazon’s current setup guide says to choose Mirror margins, enter the required value as the Inside margin, and leave Word’s separate Gutter field empty or at zero. Other software may use the gutter field differently.

Bleed vs. No Bleed Margins

No bleed means nothing intentionally extends past the final trim edge. With bleed means backgrounds, artwork, photographs, or graphics extend beyond the trim line so they print all the way to the finished edge.

For bleed interiors, Amazon currently requires artwork to extend an additional 0.125" (3.2 mm) beyond the top, bottom, and outside edges. That bleed extension is not the safe margin: one extends printable artwork outward, while the other keeps important content safely inward.

Practical 6×9 Margin Examples

Should You Use KDP’s Minimum Margins?

Not automatically. KDP’s values are manufacturing minimums, not a complete typography system. A good layout also considers readability, line length, visual balance, chapter design, headers, page numbers, book thickness, and trim size.

A small trim with long lines or crowded page furniture may need more breathing room. Do not shrink margins simply to reduce page count; a lower printing cost is not worth a cramped, less readable book.

Mirrored Margins Explained

Printed books use facing pages. The inside edge changes sides as the reader turns the page: it appears on the left side of a right-hand page and the right side of a left-hand page. Mirrored margins tell the layout program to alternate those inside and outside positions automatically.

The open-book diagram above shows the result. The binding-side margin always faces the spine even though its physical side changes from page to page.

Common KDP Margin Mistakes

• Using identical inside and outside margins without considering the binding
• Setting margins before finalizing the trim size
• Forgetting that font or line-spacing changes can alter page count
• Failing to recheck the gutter after pagination changes
• Confusing the bleed extension with the safe margin
• Adding the gutter twice in layout software
• Exporting reader spreads instead of individual pages
• Placing page numbers or headers too close to trim
• Assuming the Word document is correct without inspecting the final PDF
• Using minimum margins even when the page looks visibly cramped

Why Did KDP Flag My Margins?

Print Previewer warnings can come from text or images outside the safe area, insufficient gutter space, incorrect PDF page dimensions, a mismatch between the selected bleed setting and the file, or page content that shifted during export. The visible text may look fine while the underlying PDF page box or positioned object is wrong.

Before You Upload to KDP

• Confirm final trim size
• Confirm final page count
• Check inside margin / gutter
• Check outside margin
• Check top and bottom margins
• Confirm bleed / no-bleed selection
• Check headers
• Check page numbers
• Check chapter openings
• Check blank pages
• Check fonts
• Export individual pages rather than spreads
• Inspect the final PDF
• Review the book in KDP Print Previewer