Find the perfect trim size for your Amazon KDP paperback. Use the genre selector below to see recommended sizes, or browse the complete filterable table of all available KDP trim sizes.
Choose Your Genre
Click a genre to see the recommended trim sizes and UK publishing conventions:
Fiction / Novels
Non-Fiction / Self-Help
Memoir / Biography
Children's Books
Poetry
Textbooks / Workbooks
Photography / Art Books
Romance
Visual Size Comparison
Sizes shown at relative scale. Click a genre above to highlight recommended sizes.
Complete KDP Trim Size Table
Filter and search all available Amazon KDP trim sizes:
| Trim Size (in) | Metric (mm) | Bleed | No-Bleed | Best For | Notes |
|---|
UK Publishing Size Equivalents
For UK authors, here is how traditional British book formats map to KDP trim sizes:
| UK Format | UK Size (mm) | Closest KDP Size | KDP Size (mm) |
|---|---|---|---|
| A-format (mass market) | 110 x 178 | 5" x 8" | 127 x 203 |
| B-format (standard) | 129 x 198 | 5.25" x 8" or 5.5" x 8.5" | 133 x 203 or 140 x 216 |
| C-format (trade) | 135 x 216 | 5.5" x 8.5" | 140 x 216 |
| Demy | 138 x 216 | 5.5" x 8.5" | 140 x 216 |
| Royal | 156 x 234 | 6.14" x 9.21" | 156 x 234 |
| Crown Quarto | 189 x 246 | 7.44" x 9.69" | 189 x 246 |
You might also need
- Margin Calculator
- Spine Width Calculator
- KDP Cover Formatting Guide
- KDP Formatting Checklist
- Word to KDP Guide
Frequently asked questions
Which KDP trim size matches the UK B-format paperback?
The closest KDP equivalent to the UK B-format (129 x 198 mm) is 5.25" x 8" (133 x 203 mm) or 5.5" x 8.5" (140 x 216 mm). KDP also offers an exact 5.06" x 7.81" option that matches B-format precisely.
What trim size should I use for a children's picture book?
Square sizes like 8.25" x 8.25" or 8.5" x 8.5" suit picture books, and 8.5" x 11" works for larger illustrated titles. Bleed should be enabled so full-page illustrations extend to the trimmed edge.
Which KDP trim size is closest to the UK Royal format?
KDP's 6.14" x 9.21" (156 x 234 mm) is an exact match for the UK Royal format. It is a common choice for non-fiction and academic titles.
Can I change a KDP book's trim size after publishing?
No — trim size is locked once a book is live. To change it you have to unpublish the title, create a new edition at the new trim size, and republish with a new ISBN.
Not sure which size to pick?
Upload your manuscript and we will format it to the perfect trim size for your genre — from £69.
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