Use this checklist to choose trim size, bleed, and margins before upload so KDP Previewer checks stay cleaner and easier to understand.
Pick your trim size once and stick with it
Common trim sizes for trade paperbacks are 5 x 8, 5.25 x 8, 5.5 x 8.5, and 6 x 9. Pick the size your edition needs and keep it fixed during final proofing.
If you change trim size late, page count and layout can shift, which means you may need to redo margin checks.
It is much easier to catch print problems when the trim size stays stable from start to finish.
Choose bleed only when the page really needs it
Use bleed only when text, images, or artwork are meant to run all the way to the edge of the page.
For text-only interiors, no-bleed usually makes the final KDP check simpler.
Do not assume every image warning means you need bleed. Sometimes the real problem is that the content is too close to the safe area.
Use page count to choose a safer gutter
The inside margin usually needs to grow as page count goes up. Otherwise text can feel too close to the spine.
Use the table below as a quick working guide, then confirm current KDP requirements before final upload.
Check margins in the exported PDF, not just in the editor
Always judge margins in the final exported PDF and in KDP Previewer, not only in the writing view.
Pay extra attention to chapter-open pages, pages with ornaments, and any page with unusual spacing.
If KDP flags a page, use the exact warning text
If text looks too close to the trim edge, fix spacing or margins in the source file and export again.
If Previewer flags an image page, read the exact warning before changing bleed settings. A margin warning and a bleed warning do not point to the same fix.
If you must change trim size late, treat that as a fresh pass: export again and rerun Previewer before you publish.
Numbers and Reference Tables
Gutter Quick Reference (KDP paperback interiors)
Working reference for fast checks. Confirm latest KDP values before launch.
Final page count
Suggested inside margin (gutter)
Suggested outside margin
Practical note
24-150 pages
0.375 in (9.6 mm)
0.25 in (6.4 mm)
Good starting point for shorter books.
151-300 pages
0.50 in (12.7 mm)
0.25 in (6.4 mm)
A very common trade-paperback range.
301-500 pages
0.625 in (15.9 mm)
0.25 in (6.4 mm)
If gutter is too small here, inner text can feel cramped.
501-700 pages
0.75 in (19.1 mm)
0.25 in (6.4 mm)
Run an extra proof pass before upload.
701-828 pages
0.875 in (22.2 mm)
0.25 in (6.4 mm)
Treat this range as higher-risk for margin drift.
Publish Checklist
Lock one trim size in KDP before final proofing.
Choose bleed on purpose: yes only when content runs to the page edge.
Copy the exact warning text for image-related flags before changing bleed settings.
Record the final page count from the exact PDF you plan to upload.
Choose the inside margin from the page-count table.
Confirm the outside margin stays consistent across chapters.
Check chapter-open pages for crowding near the top, bottom, and spine side.
Check pages with ornaments or images for safe placement.
Check a few odd and even pages near the middle of the book where spine pressure is highest.
Save one screenshot of your KDP print setup (trim, bleed, paper).
Save screenshots of any margin warning page before and after fixes.
Export again after source fixes and rerun Previewer on the newest file only.
Keep one final PDF and use that exact file for upload.
Verification Checklist
Screenshots to keep for print setup
Save the KDP print setup page showing trim size, bleed, and paper settings.
Save at least two Previewer screenshots: one chapter-open page and one ornament or image page.
Save before-and-after screenshots for any margin warning you fixed.
Final margin checks before upload
Make sure the PDF page count used for your gutter decision matches the file you are uploading.
Confirm no last-minute trim or bleed changes were made after the final Previewer pass.
Spot-check a handful of random pages for consistent text distance from the trim edge.
The Senswriter way (faster)
Use the same workflow in one workspace: draft, export, run checks, fix the source, and upload one clean final file.
Write and reorganize chapters/scenes without switching between multiple tools.
Generate print-ready PDF, EPUB, and DOCX from the same manuscript source.
Re-export quickly after fixes so KDP and EPUB checks stay repeatable.
Use optional BYOK AI assist only if you want drafting support.