How KDP paperback margins work
KDP sets minimums, not recommended values. Your text, page numbers and running heads must all sit inside them. Most professionally printed books use wider margins than the minimum, especially on the outside and bottom, because they are easier to hold and read.
Inside margin (gutter) by page count
The inside margin is the one next to the binding. Thicker books curve more into the spine, so KDP asks for a wider inside margin as the page count grows:
| Page count | Minimum inside margin |
|---|---|
| 24–150 pages | 0.375 in (9.6 mm) |
| 151–300 pages | 0.5 in (12.7 mm) |
| 301–500 pages | 0.625 in (15.9 mm) |
| 501–700 pages | 0.75 in (19.1 mm) |
| 701–828 pages | 0.875 in (22.3 mm) |
The tier depends on your final page count, after front matter, back matter and any blank pages. A book that grows from 298 to 304 pages during editing moves from 0.5 in to 0.625 in. If you format in Word, KDP asks you to enter the same value for the inside margin and the gutter.
Outside, top and bottom margins
These three must be at least 0.25 in (6.4 mm) without bleed and 0.375 in (9.6 mm) with bleed. They don’t have to be equal.
Bleed and PDF page size
If any image or color runs to the edge of a page, the whole file needs bleed. KDP trims 0.125 in (3.2 mm) from the top, bottom and outside edge of every page, so a bleed PDF is 0.125 in wider and 0.25 in taller than the trim size: a 6 × 9 in book becomes a 6.125 × 9.25 in PDF. Without bleed, the PDF page is exactly the trim size. Bleed files must be uploaded as PDF.
Page-count limits
KDP paperbacks need at least 24 pages (72 for standard color). The maximum depends on the trim size and paper: up to 828 pages on white paper for most trims, fewer on cream paper and on the largest trim sizes. Printed books always have an even number of pages.
IngramSpark
IngramSpark’s file creation guide recommends a margin of at least 0.5 in (13 mm) on all sides, with the same 0.125 in bleed on the top, bottom and outside edges. For color interiors it also recommends an extra 0.125 in (3 mm) white strip on the binding side. And unlike KDP, IngramSpark requires a PDF/X-1a or PDF/X-3 file.