Self-publishing glossary. KDP and ebook terms, defined plainly.

Each term below has its own page: a definition you can quote, how the thing works, a worked example, the mistakes people make with it, and the official pages it was checked against. Figures such as royalty rates and printing costs are read from the same code our free calculators use, so the glossary and the tools agree.

0-9

35% royalty option: KDP's lower ebook royalty plan: 35% of list price, no delivery cost, and a much wider price range.
70% royalty option: KDP's higher ebook royalty plan, for list prices of $2.99 to $12.99 on Amazon.com, less a delivery cost.

A

AI-generated vs AI-assisted: KDP's two labels for AI use: disclose AI-generated content; AI-assisted needs no disclosure.
ARC (advance reader copy): A free, early copy of a book given to reviewers and readers before publication.
ASIN: The 10-character code Amazon gives every product in its catalog, each book format included.

B

BISAC subject codes: The book trade's standard subject headings, each with a nine-character code, kept by BISG.
Bleed: Image or color that runs past the trim line so it reaches the page edge once cut.

D

Delivery cost: The per-megabyte charge KDP deducts from 70%-option ebook sales.

E

EPUB: The open, W3C-maintained file format for ebooks: web content packaged into one file.
Expanded Distribution: A free KDP option that offers your paperback to distributors serving bookstores and libraries.

F

Front matter: Everything in a book before chapter one: title pages, copyright page, contents and introduction.

G

Gutter (inside margin): The inside margin of a printed book, between the text and the spine fold.

I

ISBN: A 13-digit identifier for one edition and format of a book, used by publishers, stores and libraries.

K

KDP (Kindle Direct Publishing): Amazon's free self-publishing service for Kindle ebooks, paperbacks and hardcovers.
KDP Select: An optional, renewable 90-day program that makes a Kindle ebook exclusive to Amazon in return for Kindle+.
KENP (Kindle Edition Normalized Pages): The standard page Amazon uses to count how much of a Kindle+ (formerly Kindle Unlimited) book was read.
Keywords (KDP metadata): The seven search phrases you give KDP so Amazon can match your book to shoppers' searches.
Kindle+ (formerly Kindle Unlimited): Amazon's reading subscription, formerly Kindle Unlimited, open to KDP Select books and paid by pages read.

L

Large trim: KDP's class for print books wider than 6.12 in or taller than 9 in, which cost more to print.
Lead magnet: A free, useful resource given in exchange for an email address, such as a guide or checklist.
List price: The price you set for a book on KDP, which decides the royalty option and rate.
Low-content book: A print book with little or no interior content, designed to be filled in: notebooks, planners, journals.

P

Printing cost: What KDP deducts from each paperback sale to manufacture the copy.
Public domain: Works no longer protected by copyright, which anyone may reprint or adapt without permission.

R

Reflowable vs fixed layout: Whether an ebook's text rewraps to the screen (reflowable) or keeps every page exactly as designed (fixed).

S

Spine width: The thickness of a printed book's spine, worked out from its page count and paper.

T

Trim size: The finished width and height of a printed book's pages after they are cut.

Questions, answered plainly.

Still have a question? Write to the team.

Royalty rates, list-price bands, delivery and printing costs, spine and trim figures are read from the same code as our Kindle royalty calculator and the app's KDP checks, which were checked against KDP's own help pages. Each term page says when its sources and its figures were last checked.

Mostly, because that is where most self-published books are sold. It also covers industry standards that reach beyond Amazon, such as ISBNs, EPUB and BISAC subject codes, and terms for selling direct, such as lead magnets.