KDP Trim Sizes and Margins

6 x 9 inches is the usual choice for nonfiction. It is a widely used paperback size for business, how-to, and self-help books, it prints at the lower regular-trim price, and it works on white paper, cream paper, and premium color. It also qualifies for Expanded Distribution in all three. Choose 5.5 x 8.5 for a shorter, more compact book, and a large trim such as 7 x 10 only when the layout needs the room, for example for workbooks with exercises. Large trims cost more to print, which lowers your royalty or raises the price you must charge.

Trim size also decides how many pages your words fill. Use the words to pages calculator to estimate it, and the royalty calculator to see what that trim costs to print.

The inside margin, called the gutter, is the space next to the binding. A thicker book curves more into the spine, so KDP requires a wider gutter as the page count rises. The outside, top, and bottom margins have a fixed minimum that depends on bleed.

Outside, top, bottom: 0.25 in without bleed, 0.375 in with bleed
Page size without bleed = trim size
Page size with bleed = (trim width + 0.125 in) x (trim height + 0.25 in)

Example: 6 x 9 in, 250 pages, no bleed
Gutter 0.5 in, outside 0.25 in, live area 5.25 x 8.5 in

These are minimums. Most books look better with larger margins, around 0.5 to 0.75 inches on the outside, so text does not crowd the page edge.

Bleed means artwork that runs to the very edge of the page. It matters only if your interior has images or backgrounds that reach the edge. If you use it, your PDF page is larger than the trim size, and KDP trims the extra off. A text-only interior needs no bleed.

Expanded Distribution makes your paperback available to bookstores, libraries, and other retailers outside Amazon. It is not available for every trim: the table above shows which trims qualify for each paper type. Custom trim sizes never qualify, and the royalty is 40% of the list price minus printing.