Best Trim Sizes for Amazon KDP in 2025 (Complete Guide)
By CreatorFormat Team
Choosing the right trim size (book dimensions) is one of the most important decisions in self-publishing.
In 2025, Amazon KDP supports 16+ trim sizes, but only a few perform well in sales, printing cost, and reader experience.
This guide breaks down:
- the most popular trim sizes
- recommended sizes by genre
- printing cost considerations
- mistakes to avoid
- which trim size is best for YOU
📏 What Is Trim Size?
Trim size = the final dimensions of your printed book.
Example: 6 x 9 inches
Your PDF must match the trim size exactly, or KDP will:
- distort your layout
- reject your file
- cut off margins
⭐ Top 5 Best Trim Sizes for KDP (2025)
1. 6 x 9 in (MOST POPULAR)
Best for:
- Non-fiction
- Novels
- Self-help
- Business books
✔ Cheapest print cost
✔ Most professional look
✔ Bestseller standard
2. 5.5 x 8.5 in
Great for:
- Fiction
- Romance
- YA
- Short novels
Looks more compact and reader-friendly.
3. 5 x 8 in
Best for:
- Small novels
- Poetry
- Journals
Light, portable, aesthetic.
4. 8.5 x 11 in (US Letter)
Used for:
- Workbooks
- Planners
- Coloring books
- Activity books
Large pages ideal for writing and illustrations.
5. 7 x 10 in
Perfect for:
- Guides
- Manuals
- Textbooks
More space than 6x9 without being oversized.
📚 Recommended Trim Sizes by Genre
| Genre | Best Trim Size |
|---|---|
| Non-fiction | 6 x 9 |
| Fiction | 5 x 8 or 5.5 x 8.5 |
| Romance | 5.5 x 8.5 |
| Self-help | 6 x 9 |
| Journals | 6 x 9 or 7 x 10 |
| Coloring Books | 8.5 x 11 |
| Children's Books | 8 x 10 or 8.5 x 8.5 |
| Workbooks | 8.5 x 11 |
💸 Printing Cost Considerations
Print cost depends on:
- trim size
- page count
- paper type
- ink (color/B&W)
Smaller trim sizes often cost less → more royalties.
Example:
- A 120-page 6x9 book costs less to print than a 120-page 5x8.
- Bigger pages = more ink area = higher cost.
⚠️ Avoid These Common Mistakes
- Using A4 or Letter PDFs for book interiors
- Not matching your PDF to the trim size
- Incorrect margins (KDP requires specific margins)
- Formatting text too close to edges
📐 Free Trim Size Templates
You can generate trim-size-ready formats using CreatorFormat tools for:
- 6 x 9
- 5.5 x 8.5
- 5 x 8
- 8.5 x 11
Just upload → auto-adjust → export.
🎯 Final Recommendation
If you're publishing your first book in 2025:
👉 Choose 6 x 9 in — it's the safest and most versatile trim size.
Use others only when your genre requires it.
A correct trim size =
✔ fewer KDP rejections
✔ better reader experience
✔ higher sales
More KDP formatting guides coming soon!
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