KDP Trim Sizes and Margins: Which Size for Your Book

Ruth had two books ready for Amazon at once: a 220-page cozy mystery and a 32-page picture book about her grandson's dog. She assumed one size would suit both. It would not. KDP trim sizes and margins change with the kind of book, and the margins change again with the page count.

Quick answer: For most novels pick 5.5 × 8.5 or 6 × 9 inches; for workbooks 7 × 10 or 8.5 × 11; for picture books 8.5 × 8.5, 8.25 × 8.25 or 8 × 10. Then set the inside margin from your page count, from 0.375 inch up to 150 pages to 0.875 inch past 700, and keep 0.25 inch outside, or 0.375 inch if the book uses bleed.

Every number below comes from KDP's trim size, bleed and margins page, checked in late 2026. KDP updates that page from time to time, so confirm a number there before you lay out a whole book around it.

The common KDP trim sizes

KDP prints a fixed list of paperback trims, and each has a page range that depends on the ink and paper. These are the ones most books use:

KDP also prints 5.06 × 7.81, 6.14 × 9.21, 6.69 × 9.61, 7.44 × 9.69, 7.5 × 9.25, the 8.25 × 6 landscape and A4 (8.27 × 11.69), sixteen paperback trims in all. Standard colour ink starts at 72 pages and stops at 600, so a short colour book needs premium colour, and A4 is not offered in standard colour at all. Hardcover comes in five sizes, 5.5 × 8.5, 6 × 9, 6.14 × 9.21, 7 × 10 and 8.25 × 11, from 75 to 550 pages.

If none of the sixteen fits, a paperback can take a custom size between 4 and 8.5 inches wide and 6 and 11.69 inches tall.

Which genres use which size

The genre labels in the table are habits, not rules, and they are worth following because readers notice a book that feels the wrong size in the hand.

• Novels. 5.5 × 8.5 and 6 × 9 are the safe defaults. A long epic fantasy often goes to 6 × 9 to keep the page count down.
• Literary fiction and poetry. The smaller 5 × 8 and 5.25 × 8 feel more like a bookshop paperback.
• Nonfiction. 6 × 9 for most, 7 × 10 when there are tables, recipes or diagrams.
• Workbooks and journals. 8.5 × 11 gives room to write.
• Picture books. The two squares, or 8 × 10 portrait. A landscape book can use 8.25 × 6.

KDP margins and gutter rules by page count

The gutter is the inside margin, where the pages meet the spine. A thick book bends further at the binding, so KDP asks for a wider gutter as the page count grows:

The outside, top and bottom margins have a single minimum: 0.25 inch on a book without bleed, 0.375 inch on a book with bleed. Ruth's 220-page mystery therefore needs at least half an inch at the gutter. Most designers go a little wider than these minimums so the text block does not crowd the edge.

Because the gutter depends on page count, set the trim first, estimate the pages, and only then fix the margins. A change of trim changes the page count, and that can move you into the next gutter row.

Bleed, and when you need it

Bleed is extra image past the trim so the cut never leaves a white sliver. KDP asks for 0.125 inch on the top, bottom and outside edge, but not the inside. That makes the page 0.125 inch wider and 0.25 inch taller than the trim, so an 8.5 × 8.5 picture book is laid out at 8.625 × 8.75 inches.

A text-only novel does not need bleed. A picture book almost always does. KDP's rules are firm on two points: if any page bleeds, the whole interior must be set up with bleed, and a bleed interior must be a PDF.

How to choose a trim size

1. Start from the genre. Look at three books like yours on a shelf and measure them.
2. Estimate pages. A rough guide is 250 words a page at 6 × 9; a smaller trim means more pages.
3. Check the page range. Make sure the count sits inside KDP's range for that trim, ink and paper.
4. Think about other shops. If the book will also go to IngramSpark or a bookshop, pick a size they print too.
5. Fix the margins last. Use the gutter row that matches the estimated pages.

Choose the trim on the WriterDesk

On the desk, choose Amazon KDP & Audible as the house and open Choose the trim size. The kind of book you pick (novel, handbook, picture and so on) narrows the list, and the House step shows KDP's margin rule in one line. The KDP formatting guide follows the same book through fonts, matter and ISBN.

The desk's KDP list is KDP's own: the sixteen paperback trims above, grouped by the kind of book, and nothing KDP does not print. Two things are worth knowing.

KDP has no comic trim, so a comic on KDP is offered the nearest KDP sizes, 7 × 10, 6 × 9 and 5.06 × 7.81; for the classic 6.63 × 10.25 comic page, type it into "Custom width in inches" and "Custom height in inches", which the desk holds to KDP's custom range of 4 to 8.5 wide and 6 to 11.69 tall.

A book saved earlier at a size KDP does not print, such as 10 × 8, still opens as it was; the Check step marks its trim as not a KDP size until you pick another.

The Check step then estimates your pages and spine from the word count, which tells you which gutter row to plan for. The print walkthrough shows a 6 × 9 sample, and the cover wrap guide covers the spine and barcode.

What to check before you lay out the book

• Gutter row. Recheck it after the final edit; a few thousand words can add a dozen pages.
• Bleed or not. Decide once, for the whole book.
• Colour page minimum. Standard colour needs 72 pages; a 32-page picture book uses premium colour.
• Hardcover limits. Five trims (5.5 × 8.5, 6 × 9, 6.14 × 9.21, 7 × 10, 8.25 × 11) and at least 75 pages.
• The final number. KDP's own table, not a blog post, is the last word.

Start on the WriterDesk

Open the WriterDesk, choose KDP and a trim, and let the Check step show you which margin row your book falls into.

Which size are you weighing for your book, and what kind of book is it? Write to us at [email protected].