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.
Would you rather someone else did it? Our book formatting services UK start at £69, VAT included, with files back in 24 hours.
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) | Nearest KDP Size | KDP Size (mm) |
|---|---|---|---|
| A-format (mass market) | 110 x 178 | 5" x 8" (no exact match — nearest larger option) | 127 x 203 |
| B-format (standard) | 129 x 198 | 5.06" x 7.81" | 129 x 198 |
| 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 |
Note: A-format (110×178mm) is genuinely smaller than KDP’s smallest paperback trim in both dimensions — there’s no exact KDP equivalent, so 5" x 8" (127×203mm) is only the nearest larger size KDP offers, not a true match.
Not sure which size to pick?
Upload your manuscript and we will format it to the perfect trim size for your genre — from £69.
Format my book →Related Tools
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Frequently asked questions
What is the most popular KDP trim size?
The most popular KDP trim size is 6" x 9" (152 x 229 mm). It works well for most genres including fiction, non-fiction, and memoirs. It is also the most cost-effective size for printing.
What trim size should I use for a novel?
For fiction, the most common sizes are 5" x 8", 5.25" x 8", 5.5" x 8.5", and 6" x 9". UK publishers traditionally favour the B-format (5.06" x 7.81"), but 5.5" x 8.5" is the closest KDP equivalent.
Do I need bleed for my KDP book?
You need bleed if any content (images, backgrounds, decorative elements) extends to the edge of the page. For text-only books, no-bleed is fine. Bleed adds 0.125" to the top, bottom, and outside edges.
Can I change my trim size after publishing?
You cannot change the trim size of a published book. You would need to unpublish, create a new edition with the new trim size, and republish with a new ISBN.
