Free Tool

KDP Paperback 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

Amazon.com paperback estimate. KDP hardcovers and other marketplaces use different cost tables and cover geometry.

Enable for full-bleed images or color backgrounds

Page Count

340 pages
Body text: 308 pages
Front matter: 12 pages
Back matter: 6 pages
Chapter breaks: 13 pages
Adjust assumptions

Cambric shows the manuscript as composed pages. Use the exported PDF count as the final production number.

Spine Width

0.850 inches · 21.59 mm
0.850"
0" 3"
Formula: 340 × 0.0025 = 0.850"

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

These are KDP minimums, not a complete design recommendation. Cambric shows the composed page while you choose the interior; inspect the exported PDF in KDP Print Previewer.

Cover Dimensions

Back Cover 5.5"
Spine 0.850"
Front Cover 5.5"
Full width: 12.100" Height: 8.75"
Full cover (inches) 12.100" × 8.750"
Full cover (pixels @ 300 DPI) 3630 × 2625 px
Barcode zone Use generated KDP template

Planning estimate only. Generate KDP’s official cover template from the processed interior page count before final cover export.

Printing Cost

$5.08 per copy
Fixed: $1.00 + Pages: 340 × $0.012 = $4.08 → $5.08
Cambric is $199 once. The royalty estimate below shows how many Amazon.com paperback sales at the selected price would equal that purchase.

Royalty Calculator

$
Your royalty
$3.91
per copy · 60% rate
Minimum list price
$9.99
estimated Amazon.com floor
Sell 51 copies to earn back Cambric's $199.

Amazon.com paperback estimate only

The printing-cost table, large-trim threshold, margin tiers, spine factors, and 50%/60% royalty threshold come from KDP’s current official guidance. Costs differ by marketplace. Hardcover formulas, Expanded Distribution economics, taxes, and delivery charges are outside this calculator.

Page count remains an estimate until the manuscript is typeset. Use KDP’s processed interior count and generated cover template for production, then confirm the live printing cost and royalty in Rights & Pricing.

Checked July 9, 2026: printing costs, paperback royalties, and submission margins.

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.

Replace the page estimate with the composed book.

Cambric imports or edits the manuscript beside live typeset pages. Once the interior is stable, use its actual PDF page count in KDP’s cover template and Rights & Pricing screen. Manufacturing cost and royalty still come from KDP, where marketplace and current policy are known.

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

Frequently Asked Questions

How many pages is 80,000 words?
It is only an estimate until the book is typeset. Around 280–330 pages is a useful planning range for many 5.5" × 8.5" fiction interiors, but the font, leading, margins, paragraph density, chapter starts, images, and front and back matter can move the result substantially.
What trim size should I use for my novel?
There is no universal trim size for a genre. 5" × 8", 5.5" × 8.5", and 6" × 9" create different line lengths, page counts, spines, and manufacturing costs. Check which sizes the chosen marketplace currently supports, compose representative chapters at two plausible sizes, and judge the actual page rather than treating one preset as automatically safe.
How are KDP printing costs calculated?
On Amazon.com, a regular-trim black-ink paperback from 24 through 110 pages currently costs a flat $2.30. Above 110 pages, it uses $1.00 + $0.012 per page. Large trims use $2.84 for the short tier or $1.00 + $0.017 per page above 110. Standard and premium color use their own current page ranges, fixed tiers, and per-page rates. Marketplace, trim, ink, paper, and page count all matter.
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’s current help text says spine text is printed on books with more than 79 pages, so this calculator uses 80 pages as the conservative threshold. Eligibility does not mean a long title will fit comfortably. Keep at least 0.0625" between text and each spine edge and verify KDP’s generated template.
How is the KDP paperback royalty calculated?
For Amazon.com paperbacks, the current formula is (royalty rate × tax-exclusive list price) − printing cost. The rate is 50% at $9.98 or below and 60% at $9.99 or above. Expanded Distribution uses 40% minus printing cost. This calculator models Amazon.com sales, not taxes, other marketplaces, or ebook royalties.
How accurate is this calculator?
The spine, minimum-margin, Amazon.com paperback printing-cost, and royalty formulas use current KDP documentation. Page count is a rough model, and every downstream number inherits that uncertainty. Cambric shows the actual composed pages for the manuscript; after export, use KDP’s processed page count, generated cover template, and Rights & Pricing values as the production authority.
Related

More tools & guides

Spine Width Calculator

Calculate a planning spine from page count and paper type, then verify the generated template.

Open calculator →

Cover Dimensions Calculator

Estimate KDP paperback cover dimensions, then use the generated production template.

Open calculator →

Word Count to Page Count

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

Open calculator →

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

See why Cambric beats Mac-only, cloud-centered, and retailer-limited workflows.

Read comparison →
Move from plan to pages

Estimate the economics.
Typeset the actual interior.

Cambric gives you the real composed page count, print PDF, and EPUB 3. Use KDP’s live tools for the final cover dimensions, manufacturing cost, and royalty.

Get Cambric — $199

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