Publishing glossary

Trim size: the final dimensions of your printed book.

Trim size is the finished page width and height of a printed book after the block is cut.

Checked:

6x9 inches is the KDP standardPage count changes with trim sizeThe cover must match the trim size

Choosing a trim size

Fiction usually uses 5x8 or 5.5x8.5, nonfiction and workbooks use 6x9 or larger. The trim size fixes the page dimensions for both interior and cover.

  • Pick the size before formatting
  • Changing size reflows the whole book
  • Trim size sets the spine calculation

Getting the dimensions right

The book sizes tool lists KDP's accepted trim sizes with page counts, and the cover calculator derives the matching wrap from the size you choose.

FAQ

Frequently asked questions

What is the most common KDP trim size?

6x9 inches for nonfiction and novels, with 5.5x8.5 as a close second for fiction.

Can I change trim size after formatting?

You can, but every page reflows. Choose the size first, then format once.

Put the definition to work for free.

Run your manuscript through the matching free check and see how the term applies to your own book.

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