Free tools for KDP authors
14 free tools, no account needed — built from real publishing runs, not theory. If a tool saves your book an Amazon rejection, it did its job.
Checkers & fixers
- Amazon Book Optimizer — free KDP listing checker
Paste your book’s Amazon link and get exactly what to change: the precise KDP categories to select for each format, the 7 keyword slots, plus title, series, cover and price fixes. Free, no account. - Free KDP Niche Checker — Amazon demand & competition for your book idea
Free Amazon KDP niche research tool: live Amazon search demand data plus an honest verdict on competition, how to differentiate, and narrower sub-niches with better odds. - KDP AI Disclosure Guide — do you need to declare AI content on Amazon?
Free interactive guide to Amazon KDP's AI content policy: AI-generated vs AI-assisted, what you must disclose when publishing, and how to answer the KDP form. Updated for current KDP rules. - KDP Cover Match Checker — does your cover text match your metadata?
Free KDP pre-submission check: upload your cover and enter your planned title, subtitle, and author name. AI reads the cover and flags any verbatim mismatch — the #1 cause of silent KDP rejections. - KDP Rejection Decoder — why did Amazon reject your book?
Free guided tool that decodes KDP rejections: answer a few questions and find the mechanical mismatch — cover vs metadata, spine width, ISBN, red-outlined field — behind the silent 'back to Draft' loop.
Calculators
- KDP Ads Break-Even Calculator — can Amazon Ads pay off for your book?
Free Amazon Ads break-even calculator for KDP books: enter list price, page count, and cost per click to see your royalty per copy, break-even conversion rate, and target ACOS. - KDP Margin Calculator (2026) — gutter, page size, and why Print Previewer doesn't match
Free Amazon KDP margin calculator: enter trim size and page count to get the exact inside (gutter) margin, outside margins, and PDF page size KDP checks — plus the 5 reasons Print Previewer doesn't match your file. - KDP Paperback Royalty Calculator (2026)
Free Amazon KDP paperback royalty calculator. Enter your page count and list price to see printing cost and exactly what you earn per sale — including the 60% tier at $9.99 and an Expanded Distribution comparison. - KDP Payment Schedule Calculator (2026)
When does Amazon KDP actually pay you? Royalties arrive about 60 days after the end of the month of the sale (90 for Expanded Distribution). Pick your sale month and see your payment date. - KDP Spine Width Calculator (2026) — exact spine + full cover size
Free Amazon KDP spine width calculator. Enter page count and paper type to get the exact spine width and full paperback wrap-cover dimensions with bleed — the numbers KDP checks on upload. - Kindle Royalty Calculator (2026) — updated for KDP's new $12.99 70% band
Free KDP royalty calculator, updated for Amazon's 2026 change: the 70% band now reaches $12.99. Ebook royalties with delivery fees, paperback printing costs, and KENP page-read earnings — no email required.
Generators & research
- Free Book Description Generator — Amazon KDP blurb, categories & keywords
Free book description generator for Amazon KDP. Write your book's description, then get the exact categories to select, all 7 search keywords, the reading age, and step-by-step upload instructions. Works before your book is published. No account. - Get book ideas that sell
Tap once for three researched book ideas — the niche, the buyer, and why each sells on Amazon KDP. Pick one and start writing it instantly.
Guides & answers
- Can You Change Trim Size on a Published KDP Book?
No — trim size is locked once a KDP paperback is live. Changing it means a new ISBN and ASIN, and your reviews only survive if the editions get linked. Here's the full playbook.
Prefer it done for you?
The tools are free forever. If you'd rather hand the whole thing off — interior, cover wrap, EPUB, and your Amazon listing — there's a done-for-you formatting service with a free preview chapter before you pay anything.