Free tools for the book business.
Fifteen calculators and generators for self-published authors — royalties, cover sizes, ad math, and the fiddly parts of a KDP listing. Every tool works without a signup, and the numbers match how Amazon actually pays.
Calculators
KDP Royalty Calculator
Exact royalty per book — ebook, paperback, hardcover, every marketplace.
KDP Cover Size Calculator
Full-cover and spine dimensions from trim size, page count, and paper.
ACOS Calculator
Your ACOS and break-even ACOS, built on real royalties — not list price.
Amazon Ads Cost Calculator
What a sale really costs, from CPC, clicks, and conversion rate.
BSR to Sales Calculator
Best Sellers Rank into estimated daily and monthly sales.
KENP Calculator
Kindle Unlimited page reads into an estimated payout.
Series Read-Through Calculator
Read-through between books, and where your series leaks readers.
KDP Book Price Calculator
The list price that earns the most per sale, ebook and print.
Word Count to Page Count
Words into printed pages by trim size and font.
Generators & finders
Book Title Analyzer
How your title reads in Amazon search — before you commit to it.
Amazon Category Finder
KDP category paths you can actually rank in.
Book Description Generator
A selling description with KDP-ready HTML formatting.
Copyright Page Generator
A complete copyright page — rights text, ISBN, edition, disclaimers.
ISBN Barcode Generator
Print-ready ISBN-13 barcode for your back cover.
A+ Content Template Builder
Module layouts and exact image sizes for Amazon A+ Content.
These tools estimate. The SelfPub Go desktop app tracks the real thing — what your Amazon Ads cost and what your books earn, per book, in real time. Apply for early access