KDP guide
Margins, bleed and page size of a paperback
A wrong margin is one of the most common reasons KDP rejects an interior. Here are the numbers, checked against KDP help on October 17, 2026.
Minimum margins
The inside margin, next to the spine, grows with the page count, because a thicker book swallows more paper in the binding. The other three do not change.
| Pages | Inside (gutter) | Top, bottom, outside, no bleed | Top, bottom, outside, with bleed |
|---|---|---|---|
| 24 to 150 | 0.375 in (9.6 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 151 to 300 | 0.5 in (12.7 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 301 to 500 | 0.625 in (15.9 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 501 to 700 | 0.75 in (19.1 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 701 to 828 | 0.875 in (22.3 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
Bleed and page size
The printer trims 0.125 in (3.2 mm) from the top, bottom and outside edge. For an image or color to reach the edge, it extends past that trim. A page with bleed is the trim width plus 0.125 in and the trim height plus 0.25 in.
| Trim (width × height) | Page with bleed |
|---|---|
| 5 × 8 in | 5.125 × 8.25 in (130.2 × 209.5 mm) |
| 5.5 × 8.5 in | 5.625 × 8.75 in (142.9 × 222.3 mm) |
| 6 × 9 in | 6.125 × 9.25 in (155.6 × 235 mm) |
| 7 × 10 in | 7.125 × 10.25 in (181 × 260.3 mm) |
| 8 × 10 in | 8.125 × 10.25 in (206.4 × 260.3 mm) |
| 8.5 × 8.5 in | 8.625 × 8.75 in (219.1 × 222.3 mm) |
| 8.5 × 11 in | 8.625 × 11.25 in (219.1 × 285.8 mm) |
The trim size also decides the printing cost. See it in the spine and royalty calculator.
Frequently asked questions
What is the minimum margin of a KDP paperback?+
The inside margin (gutter) depends on the page count: 0.375 in from 24 to 150 pages, 0.5 from 151 to 300, 0.625 from 301 to 500, 0.75 from 501 to 700 and 0.875 from 701 to 828. The top, bottom and outside margins are at least 0.25 in without bleed and 0.375 in with bleed.
What is bleed and do I need it?+
The printer trims 0.125 in (3.2 mm) from the top, bottom and outside edge of every page. If anything in your interior, such as a background color or an image, reaches the edge, it has to extend past that trim: that is bleed. The page becomes 0.125 in wider and 0.25 in taller. With nothing touching the edge, you do not need it.
How many pages can a paperback have?+
From 24 to 828 pages. In standard color, from 72 to 600. Above the maximum KDP does not print.
Which trim size should I choose?+
KDP offers more than twenty sizes. The choice affects cost: above 6.12 in wide or 9 in tall the book counts as large, and printing costs more. Try your case in the spine and royalty calculator.
CoAuthor builds the interior already with KDP margins
The account is free. The book costs from about US$ 7.70 (R$ 39, paid once, with no monthly fee). You are charged in Brazilian reais; the dollar figure uses the October 17, 2026 rate, about R$ 5.08 per US$ 1.