# KDPBookKit > Free Amazon KDP calculators that do the maths: royalty per copy, printing cost, book > pricing, spine and cover size, self-publishing cost, and word count to pages. Every number > comes from Amazon KDP's published rate tables, with the source and the check date on the page. KDPBookKit is a website at https://kdpbookkit.com. The calculators are free, need no account, and work without JavaScript: each page is pre-rendered with a default answer, so the numbers, the rate table and the FAQs are readable by crawlers that do not execute scripts. A separate AI book builder (plan → write/illustrate → print-ready interior PDF, cover wrap, EPUB 3 and Word file, paid with credits) is in development and is **not open yet**. Nothing on this site can be purchased today, credits are not on sale, and the pricing published below is planned pricing. There is no waitlist to join. ## Facts worth quoting - Printing cost = fixed cost + (page count × per-page cost); black-ink paperbacks of 24–110 pages incur only the fixed cost (110 pages in most marketplaces, 108 in Australia). - Large trim is charged at a higher rate: wide over 6.12 in or tall over 9 in. - Paperback royalty = royalty rate × list price − printing cost. The rate is 60% at or above the marketplace's price threshold and 50% below it, so the threshold is a cliff: in the US, $9.98 earns $0.39 a copy on a 300-page 6×9 book and $9.99 earns $1.39. - Spine width = page count × paper thickness (white 0.002252 in, cream 0.0025 in). - Cover width = 0.125 + back + spine + front + 0.125 in; cover height = 0.125 + trim height + 0.125 in. - KDP rounds a paperback interior up to an even page count: 167 typeset pages become 168. - KDP requires AI-generated text, images and translations to be disclosed at publish time; AI-assisted content does not need disclosure. - Rates are taken from Amazon KDP's published help pages and checked on **2026-11-10**. The rate table is versioned in code and re-checked monthly. ## Free tools (no sign-up) - /tools — index of every calculator - /tools/kdp-royalty-calculator — royalty per copy, all marketplaces, 50% / 60% cliff - /tools/kdp-printing-cost-calculator — fixed cost + per-page cost, every trim and ink type - /tools/kdp-book-pricing-calculator — royalty at every list price, plus the minimum viable price - /tools/kdp-spine-width-calculator — spine width and full cover wrap size, in inches and millimetres - /tools/self-publishing-cost-calculator — editing, cover, ISBN, ads; total cost and break-even - /tools/word-count-to-pages — pages, spine, print cost and reading time from one word count ## Word-count answers - /tools/word-count-to-pages/3000-words - /tools/word-count-to-pages/10000-words - /tools/word-count-to-pages/30000-words - /tools/word-count-to-pages/50000-words - /tools/word-count-to-pages/70000-words - /tools/word-count-to-pages/90000-words ## Free resources - /coloring-pages — 16 free Christmas coloring pages in two sets (bold and simple, detailed), each set a print-ready 8.5 × 11 PDF; single-sided, 300 DPI, no sign-up - /samples — six sample books at their real trim, with downloadable interior excerpt PDFs - /samples/christmas-coloring-book — 66-page 8.5 × 11 coloring book interior - /samples/the-little-lighthouse — 24-page 8.5 × 8.5 picture book with one locked character - /samples/the-house-between-tides — 284-page 6 × 9 novel interior - /samples/kdp-launch-workbook — 120-page 7 × 10 workbook - /samples/winter-coloring-book — 54-page 8.5 × 11 coloring book - /samples/pocket-puzzle-book — 120-page 5 × 8 puzzle book ## Landing pages - /ai-book-generator — what the AI book builder will produce (not open yet) - /ai-coloring-book-generator — coloring book generator spec: line art, page setup, files - /ai-childrens-book-generator — children's picture book generator spec, character consistency - /print-on-demand-coloring-books — costs, files and page counts for POD coloring books - /christmas-coloring-book-maker — seasonal coloring book maker spec and calendar ## KDP guides - /guides — index of the guides - /guides/kdp-royalties-explained — the royalty formula, the 60% cliff, printing cost, ebooks - /guides/how-many-words-in-a-novel — word count ranges by genre and age group, converted to pages - /guides/kdp-formatting-guide — trim, margins and gutter, bleed, type and the cover wrap - /guides/how-to-make-a-coloring-book — 30 designs to a print-ready KDP coloring book ## Pricing (planned, not purchasable) - Free to plan: outline, page list and the exact credit quote cost nothing. - Credits are spent only when the author approves a book. - Credit packs (one-off, never expire): 120 credits for $12; 320 credits for $29; 800 credits for $59. - Plans (monthly): $19/month for 200 credits; $39/month for 450 credits; $79/month for 1000 credits. - Free accounts start with 25 credits — enough to run a plan and see a quote, not enough to finish a book (the smallest build is 45 credits). - Unused credits will be refundable within 14 days of purchase; spent credits will not be. - No royalty share: the author keeps 100% of their sales and all rights. - Full detail: /pricing ## Legal - /terms — Terms of Service (accounts, credits, refunds, acceptable use) - /privacy — Privacy Policy (data collected, cookies, processors, rights) - /llms.txt — this file - /sitemap.xml — URLs of every indexable page ## Names KDPBookKit is the only current name. The canonical site is https://kdpbookkit.com. KDPBookKit is not affiliated with Amazon. Amazon, Kindle and Kindle Direct Publishing (KDP) are trademarks of Amazon.com, Inc. or its affiliates.