Free Tool

KDP Book Calculator

Enter your word count and see the page count, spine, cover dimensions, margin requirements, printing cost, and royalty math that shape the finished book.

Your Book

Paper
Binding

Enable for full-bleed images or color backgrounds

Page Count

324 pages
Body text: 294 pages
Front matter: 12 pages
Back matter: 6 pages
Chapter breaks: 12 pages
Adjust assumptions

Cambric calculates exact pages from your actual manuscript — no estimating.

Spine Width

0.870 inches · 22.10 mm
0.870"
0" 3"
Formula: 324 × 0.0025 + 0.06 = 0.870"

Margin Requirements

Gutter (inside) 0.625"
Outside 0.25"
Top 0.25"
Bottom 0.25"
0.25"
0.625"
0.25"
0.25"
Live area
Recto (right) page

Cambric applies correct margins automatically — zero KDP rejections.

Cover Dimensions

Back Cover 5.5"
Spine 0.870"
Front Cover 5.5"
Full width: 11.870" Height: 8.5"
Full cover (inches) 11.870" × 8.5"
Full cover (pixels @ 300 DPI) 3561 × 2550 px
Barcode zone 2" × 1.2" on back

Cambric generates a cover template with exact dimensions for your designer.

Printing Cost

$6.51 per copy
Fixed: $2.30 + Pages: 324 × $0.013 = $4.21 → $6.51
A professional formatter charges $150–$300 per book. Cambric is $199 once, for every book you'll ever write.

Royalty Calculator

$
Your royalty
$2.48
per copy
Minimum list price
$10.85
at 60% royalty
Sell 81 copies to earn back Cambric's $199.

KDP vs IngramSpark

KDP IngramSpark
Print cost $6.51 ~$7.16
Royalty at list $2.48 ~$0.58
Distribution Amazon 40,000+ retailers
Setup fee Free Free
Returns No Optional

Cambric exports print-ready files for both KDP and IngramSpark.

Skip the math. Try Cambric.

You'll redo this every time your book changes.

The numbers above are based on the word count and settings you entered. But every formatting decision changes them:

Change font
Pages change
Change trim
Cost changes
Edit manuscript
All of it shifts
Switch platform
Different specs

Page count, cost, spine width, margins, royalty — they're all connected. Change one variable and you're back here recalculating. And these are estimates based on words-per-page formulas, not your actual formatted manuscript.

In Cambric, these numbers come from your actual book.

Import your manuscript, pick a template, choose your trim — and see real page count, real spine width, real printing cost, and real royalty. Not estimates from a formula. The actual numbers from your typeset book. Change your font, add a chapter, switch trim size — everything recalculates instantly.

Get Cambric — $199 One-time purchase. Your files stay on your machine.

Frequently Asked Questions

What trim size should I use for my novel?
The most popular trim size for fiction is 5.5" × 8.5". It's the standard trade paperback size you see on bookstore shelves. Romance and thrillers often use 5" × 8" for a more compact, pocket-friendly feel. Fantasy and sci-fi sometimes go with 6" × 9" for longer books. Nonfiction commonly uses 6" × 9" as well. If you're unsure, 5.5" × 8.5" is always a safe choice.
How are KDP printing costs calculated?
KDP uses a fixed cost plus a per-page cost. For black-and-white paperbacks, it's $2.30 + $0.013 per page. Premium color is $3.80 + $0.042 per page, and standard color is $2.30 + $0.02 per page. Hardcovers have different fixed costs. The per-page cost is based on the total page count, including front matter, back matter, and any blank pages. Larger trim sizes (over 6.12" wide or 9" tall) have higher per-page rates.
What's the minimum margin for KDP?
KDP requires a minimum outside margin of 0.25" (top, bottom, and outside edge) for books without bleed. With bleed enabled, the minimum increases to 0.375". The inside (gutter) margin depends on page count: 0.375" for 24–150 pages, 0.5" for 151–300 pages, 0.625" for 301–500 pages, 0.75" for 501–700 pages, and 0.875" for 701–828 pages. These are minimums — most professionals use slightly larger margins for better readability.
Can I put text on the spine?
KDP requires a minimum of 79 pages before spine text is allowed. Below that, the spine is too narrow for text to be legible and properly aligned during binding. For a 79-page cream book, the spine is roughly 0.26" — tight but workable. Most books over 100 pages have plenty of spine room. The calculator above shows your exact spine width and whether it qualifies for spine text.
What's the difference between KDP and IngramSpark?
KDP (Kindle Direct Publishing) is Amazon's print-on-demand service. Your book is available on Amazon with the best royalty rate (60%). IngramSpark distributes to 40,000+ retailers including bookstores, libraries, and online stores worldwide. Many indie authors use both: KDP for Amazon (better royalty) and IngramSpark for everywhere else (wider distribution). Both are free to set up. The main trade-off is royalty rate vs. distribution reach.
How accurate is this calculator?
This calculator uses KDP's official formulas for spine width, margins, and printing costs. Page count is an estimate based on industry-standard words-per-page for each trim size at 11pt with 1.15 line spacing. Your actual page count will depend on your specific font, spacing, and formatting choices. For exact page counts based on your actual manuscript, Cambric calculates the real number from your typeset pages — no estimating required.
Common Questions

KDP Calculator FAQ

How many pages is 80,000 words in a book?
An 80,000-word book is typically 280–320 pages at a 5.5" × 8.5" trim size with standard formatting (11–12pt font, 1.3–1.5 line spacing). The exact count depends on your trim size, font, margins, and front/back matter. Use the calculator above for a precise estimate.
What trim size should I use for my book?
5.5" × 8.5" is the most popular trim size for fiction (romance, thriller, literary). 6" × 9" works well for nonfiction and longer fiction (epic fantasy, sci-fi). 5" × 8" gives a mass-market paperback feel. Your choice affects page count, printing cost, and margin requirements. See our complete KDP formatting guide for detailed trim size recommendations by genre.
How much does it cost to print a book on KDP?
KDP printing cost is based on page count, trim size, ink type (black or color), and marketplace. A typical 300-page black-and-white 5.5" × 8.5" paperback costs about $4.45 to print in the US marketplace. The calculator above shows exact costs for your specifications.
What margins does KDP require?
KDP minimum margins depend on page count. For books under 150 pages: 0.375" inside margin. For 150–400 pages: 0.5" inside. For 400–600 pages: 0.625" inside. Top and outside margins must be at least 0.25". Professional book formatters typically use wider margins than these minimums for better readability. If your PDF was rejected, see our guide on fixing KDP file rejections.
How is KDP royalty calculated?
KDP paperback royalty = (List Price × 60%) − Printing Cost. For example, a $14.99 book with $4.45 printing cost earns $14.99 × 0.60 − $4.45 = $4.54 per copy. Expanded distribution royalty uses 40% instead of 60%. Ebook royalty is 70% of list price minus a delivery fee, or 35% with no delivery fee.
What is spine width and how do I calculate it?
Spine width is the thickness of your book's spine, measured in inches. It's determined by page count and paper type. For white paper: pages × 0.002252". For cream paper: pages × 0.0025". A 300-page book on cream paper has a spine of about 0.75". You need this measurement to design your book cover.
Related

More tools & guides

Spine Width Calculator

Calculate exact spine width for your cover template from page count and paper type.

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Cover Dimensions Calculator

Generate exact cover dimensions including bleed, spine, and barcode placement.

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Word Count to Page Count

Estimate page count from word count based on trim size and font choice.

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How to Format for KDP

Step-by-step formatting guide for Amazon KDP print-ready PDFs.

Read guide →

KDP Requirements

Complete file specifications and margin rules for Amazon KDP.

Read guide →

Formatting Software Compared

Cambric, Vellum, Atticus, and more — side-by-side comparison.

Read comparison →
Stop Estimating

You just estimated by formula
what Cambric calculates from your real book.

Page count, spine width, printing cost, royalty — all calculated from your actual formatted manuscript, not a words-per-page formula. Change anything, everything updates.

Get Cambric — $199

One-time purchase · macOS & Windows · Your files never leave your machine