You finished the book. The hard part is over. But now KDP is asking for margins, fonts, page numbers, headers, and a paperback-ready PDF, and suddenly you’re back to feeling lost.
Here’s the truth: KDP manuscript formatting isn’t complicated, but the rules aren’t obvious either. Get them wrong and KDP rejects your file. Get them right and your book looks like it came from a real publisher.
This is the practical step-by-step guide for indie authors formatting their first KDP paperback in 2026.
What KDP Actually Requires
Before you change a single setting, understand what KDP cares about:
- Your trim size matches one of their supported sizes
- Your margins are big enough (especially the inside margin)
- Your fonts are embedded in the PDF
- Your interior is a single PDF file (not a Word doc)
- The page count is right for the spine width
- Your PDF doesn’t have any errors that flag the print-ready check
That’s it. Everything else (font choice, line spacing, drop caps) is up to you.
Step 1: Pick Your Trim Size
Trim size is the physical dimension of your printed book. The most common choices for indie authors:
- 5 x 8 inches: Compact, classic novel size. Cheaper to print.
- 5.5 x 8.5 inches: The most popular size for paperback fiction.
- 6 x 9 inches: Standard for nonfiction and longer novels. Looks more substantial.
- 8.5 x 11 inches: Workbooks, journals, large-format nonfiction.
Pick one and stick with it. Switching later means reformatting the entire book.
Step 2: Set Your Margins
This is where most authors mess up. The inside margin (gutter) needs to be bigger than the outside margin so your text doesn’t disappear into the spine.
For a typical 5.5 x 8.5 inch paperback:
- Top margin: 0.75 inches
- Bottom margin: 0.75 inches
- Outside margin: 0.5 inches
- Inside margin (gutter): 0.75 inches
For longer books (300+ pages), bump the inside margin to 0.875 or 1 inch. The thicker the spine, the more margin you need.
Step 3: Choose Your Fonts
The body font affects readability more than anything else. Use a serif font for fiction. Sans-serif fonts feel cold and corporate for novels.
Good body fonts:
- Garamond (classic, slightly tighter)
- Caslon (warm and readable)
- Sabon (modern serif)
- Cardo (free alternative to Adobe fonts)
Body font size for a 5.5 x 8.5 paperback: 11 to 12 points. Line spacing: 1.15 to 1.3.
For chapter headings, you can use a different font (often a sans-serif or display serif) for visual contrast. Just don’t use more than two or three fonts total.
Step 4: Set Up Headers and Page Numbers
Open your manuscript in Word or Google Docs. Insert a header. Then add:
- Even pages (left side): Author name
- Odd pages (right side): Book title or chapter title
Page numbers go in the footer or the header outside corners. Don’t put them on chapter title pages or front matter pages (title page, copyright, dedication).
This is fiddly. In Word, you’ll need to use Section Breaks to control which pages get headers and which don’t. The first time you do this, set aside an afternoon. After that, it’s muscle memory.
Step 5: Format Your Front Matter
Every paperback needs:
- Half title page: Just the title, centered, alone on the page
- Title page: Title, subtitle, author name, publisher (your imprint)
- Copyright page: ISBN, copyright notice, edition info, “All rights reserved” line, your imprint
- Dedication (optional): One line, centered
- Table of contents (for nonfiction): Or skip for fiction
These all start on the right-hand page (odd page numbers). Use blank pages to make the math work if needed.
Step 6: Chapter Pages
Every chapter starts on a new page. Best practice: chapters start on the right-hand page (odd page) for premium feel. This costs extra blank pages but looks much better.
Each chapter title page:
- Top half blank or with a small ornament
- Chapter number or title centered, larger font
- Two or three blank lines
- First paragraph (no indent on the very first paragraph of the chapter)
Step 7: Export to PDF
This is where most rejections happen. Export settings matter.
In Word: File > Save As > PDF > Options > check “ISO 19005-1 compliant (PDF/A)” if you want maximum compatibility.
In Google Docs: File > Download > PDF Document.
In Affinity Publisher (best option for Windows authors): File > Export > PDF for Print > PDF/X-1a:2003.
Always:
- Embed all fonts
- Don’t compress images below 300 DPI
- Don’t use transparency in the body of the book
Step 8: Run It Through a Checker
This is where BookReady comes in. Upload your PDF to our free KDP PDF checker (or the IngramSpark version if you’re publishing on both). It tells you immediately if there are issues:
- Trim size mismatch
- Embedded font problems
- DPI issues with images
- Bleed and margin warnings
Catching this before you upload to KDP saves days of back-and-forth rejections.
Common KDP Rejection Reasons
These are the issues we see most often:
- Trim size doesn’t match. Your PDF is 8.5x11 but you selected 6x9 in KDP.
- Margins too tight. Inside margin under 0.5 inches gets flagged.
- Fonts not embedded. Some fonts (especially free ones) aren’t licensed for embedding.
- Bleed mismatch. If you have full-page images, you need 0.125-inch bleed. If you don’t, set bleed to 0.
- Odd page count. Paperbacks need an even page count. Add a blank page if needed.
Tools That Make This Faster
- Affinity Publisher: $69 one-time fee. Best paid option for indie authors. Way better than Word for layout.
- Vellum: Mac only. Beautiful output. Limited customization.
- BookReady: Free PDF checker for KDP and IngramSpark. Catches the most common rejections before submission.
- Atticus: Cross-platform. Subscription model.
If you’re on Windows and want a real layout tool, Affinity Publisher is the answer.
Final Thoughts
The first book you format will take a long weekend. The second book takes an afternoon. The third book takes an hour. After that, you have a template and you’ll wonder why you ever found this hard.
Don’t overthink fonts and margins. Pick something readable, embed everything, and run the file through a checker before uploading. That’s 90 percent of getting this right.
Your readers won’t notice good formatting. They WILL notice bad formatting. Get the basics right and let your story do the rest.
FAQs
Q: Can I just use Word for KDP formatting?
A: Yes, but it’s painful for longer books. Word’s section breaks are buggy. If you’re publishing multiple books, invest in Affinity Publisher or Vellum. Worth it.
Q: What page count does KDP support?
A: Minimum 24 pages. Maximum 828 pages for 5x8 paperback (varies by trim size and paper).
Q: Do I need bleed?
A: Only if you have images that go to the edge of the page. Most novels don’t need bleed. Picture books and illustrated books always do.
Q: What font size should I use for a novel?
A: 11-point Garamond or 12-point Cardo are both safe choices. Avoid anything below 10-point or above 13-point in body text.
Q: How do I check my PDF’s DPI?
A: Use BookReady’s free KDP PDF checker. It reports DPI, fonts, trim size, and bleed in seconds.