Skip to content
iLoveKDP

Choosing a trim size

Trim size is the finished size of the book. It fixes the cover, the margins and the page count, so it is the first decision rather than the last.

Last reviewed

What trim size decides

Trim size is the finished width and height of the book after it is cut. It is the first decision in a print book because nearly everything else follows from it: how many words fit on a page and therefore the page count; the margins and live area; and the dimensions of the cover.

The sizes this app supports

KDP offers more trim sizes than these, including custom sizes. These are the common ones the calculators and generators in this app support, and the bindings each is offered for here:

  • 5" x 8" — paperback and hardcover
  • 5.5" x 8.5" — paperback and hardcover
  • 6" x 9" — paperback and hardcover
  • 7" x 10" — paperback and hardcover
  • 8.5" x 11" — paperback and hardcover
  • 8.25" x 6" — paperback only
  • 8.25" x 8.25" — paperback only

Choosing one

Convention is the best guide, and it is genre-specific. Measure books similar to yours. As general guidance rather than a rule:

  • 5" × 8" and 5.5" × 8.5" are common for fiction and memoir; they feel like a familiar paperback.
  • 6" × 9" is the most common size for non-fiction and a frequent default for fiction too.
  • 7" × 10" and 8.5" × 11" suit workbooks, textbooks, journals and planners where writing space matters.
  • 8.25" × 8.25" and 8.25" × 6" suit picture books and illustrated books in square and landscape formats.

Hardcover availability

In this app, hardcover is offered for 5" x 8", 5.5" x 8.5", 6" x 9", 7" x 10", 8.5" x 11", and not for 8.25" x 6" or 8.25" x 8.25". KDP's list of hardcover trims is narrower than its paperback list and has changed over time, so confirm on KDP before planning a hardcover in a less common size.

Changing trim later

Changing trim after the interior is laid out reflows every page, changes the page count, changes the gutter, and changes the spine and cover. It is possible, but it is a rebuild of both files rather than an adjustment.

What to do

  1. Look at books in your genre and measure the ones a reader would shelve yours beside.
  2. Choose the trim before laying out the interior; changing it later reflows every page.
  3. Check that the trim is offered for the binding you want before committing to it.

Try a trim size, free — no account needed, no upload, the answer in the page.Or compare trim sizes in the workspace to save it against a book.

Related