Setting Correct Page Margins for Print-on-Demand Books in Word
The correct page margins for a print-on-demand book depend on which platform you’re publishing to and how many pages your book has. On Amazon KDP, the inside (gutter) margin starts at 0.375″ for shorter books and scales up to 0.75″ for books over 500 pages. On IngramSpark, a flat minimum of 0.5″ on all sides applies. Setting these values in Microsoft Word takes about five minutes once you know where to look — but getting them wrong means your book will be rejected or will print with text running into the spine.
The Four Margin Zones and Why the Gutter Is Always the Largest
Every page in a print book has four margin zones: inside (gutter), outside, top, and bottom. The gutter is the margin along the spine edge — the side where pages are bound together. Because the spine binding physically consumes space, text near the gutter gets harder to read as the book thickens. This is why the inside margin is always set larger than the other three.
The outside margin is the edge opposite the spine — the side you grab when holding the book. Top and bottom margins frame the text block vertically and typically also contain headers, footers, and page numbers. All four zones must clear the platform’s minimums, but the gutter minimum changes based on page count in a way the other three don’t.
KDP Margin Requirements by Page Count
Amazon KDP uses a sliding scale for the inside margin that increases as your page count grows. The current minimums are:
- 24–150 pages: 0.375″ gutter
- 151–300 pages: 0.5″ gutter
- 301–500 pages: 0.625″ gutter
- 501–700 pages: 0.75″ gutter
The outside, top, and bottom margins on KDP must be at least 0.25″ for standard (non-bleed) books. If your book contains any elements that bleed to the edge of the page — such as a full-page illustration or a background colour that runs to the trim — those three margins increase to a minimum of 0.375″.
One important consequence of this structure: if you’re near a page-count boundary, adding or removing content can push you across a threshold and require a larger gutter. A manuscript sitting at 299 pages and a manuscript sitting at 301 pages have different minimum gutter requirements. Check your final page count before finalising your margins.
IngramSpark Margin Guidelines
IngramSpark uses a simpler, uniform approach. The recommended minimum is 0.5″ (approximately 13 mm) on all four sides, with an optional inside margin of 1″ (25 mm) for added spine safety. Unlike KDP, IngramSpark does not vary the gutter requirement by page count — the same 0.5″ minimum applies whether your book is 100 pages or 600.
That said, IngramSpark distributes to a wider range of retailers and print facilities, and slight trim variation across different print sites is a real consideration. Using the full 1″ inside margin recommendation for longer books is a reasonable precaution even if it isn’t formally required.
How to Set Mirror Margins in Microsoft Word
For a print book, you need mirror margins — the inside and outside margins swap positions between left and right pages, just as in a printed book. Word’s standard margin settings don’t do this by default. Here’s the process:
- Go to Layout (or Page Layout in older versions) → Margins → Custom Margins.
- In the Multiple pages dropdown, select Mirror margins. The “Left” and “Right” fields will change to “Inside” and “Outside”.
- Set your Inside margin to the appropriate gutter value for your page count and platform.
- Set Outside, Top, and Bottom to at least the platform minimums (typically 0.25″–0.5″).
- Click OK, then apply to the whole document.
Before setting margins, make sure your page size in Word matches your book’s trim size. Go to Layout → Size → More Paper Sizes and enter your trim dimensions (common sizes are 5″ × 8″, 5.5″ × 8.5″, and 6″ × 9″). Margin values are calculated relative to the page size, so this step must come first.
If you’d rather start with a correctly configured file, KDP provides free Word manuscript templates for common trim sizes. These come pre-set with the right page dimensions and margin values, which removes one potential source of error.
Common Margin Mistakes That Cause Rejection
The most frequent margin-related rejection on both KDP and IngramSpark is insufficient gutter margin — either using a flat margin value without accounting for page count, or forgetting to enable mirror margins so the inside and outside margins are correctly positioned. If Word is set to standard (non-mirrored) margins, both sides of every spread will have identical margins, which means the binding side won’t have the extra space it needs.
Other common errors include leaving the page size in Word at the default 8.5″ × 11″ while working in a 6″ × 9″ trim — this causes the calculated margins to be wrong even if the numbers look correct — and placing running headers or page numbers outside the margin boundary, which KDP will flag during its automated preflight check.
Bleed and How It Changes the Picture
Bleed applies when any image, colour, or design element is intended to print right to the edge of the trimmed page. Most text-only interiors don’t need bleed. If yours does — for example, a cookbook with full-page photos or a children’s book with full-colour backgrounds — the minimum margins on the outside, top, and bottom edges increase on KDP (to 0.375″), and you’ll need to add 0.125″ of bleed beyond the trim size on all edges.
IngramSpark handles bleed similarly: bleed elements must extend 0.125″ beyond the trim, and all live content (text, logos, anything that must not be cut) should sit at least 0.125″ inside the trim edge. The inside margin stays at the standard minimum regardless of bleed.
Practical Margin Settings to Start With
If you want working defaults that meet both KDP and IngramSpark requirements for a standard novel-length paperback (200–300 pages) in a 6″ × 9″ trim, these settings are a reliable starting point:
- Inside (gutter): 0.75″ — comfortably above both platforms’ requirements and safe for books approaching the 300-page threshold
- Outside: 0.5″
- Top: 0.75″
- Bottom: 0.75″
These values give you a reading-friendly text block with enough margin safety to absorb minor trim variation. Once you know your final page count and platform, you can tighten or adjust as needed — but starting here avoids the most common rejection reasons before you’ve even submitted.
