Book Trim Sizes Explained
Find the right size for your book.
Your trim size affects everything — margins, font size, page count, printing cost, and how your book feels in readers' hands. These guides cover the specs for every popular size.
Quick comparison
| Trim Size | Best For | Page Count (80K words) | Guide |
|---|---|---|---|
| 5" × 8" | Romance, thriller, mystery | ~340 pages | View guide → |
| 5.25" × 8" | General fiction | ~310 pages | View guide → |
| 5.5" × 8.5" | All fiction, memoir | ~280 pages | View guide → |
| 6" × 9" | Nonfiction, literary fiction | ~230 pages | View guide → |
| 8.5" × 11" | Workbooks, textbooks | ~145 pages | View guide → |
| Large Print | Accessible editions | ~420 pages | View guide → |
Choose your trim size
Each guide covers margins, font recommendations, spine width, printing costs, and KDP/IngramSpark requirements for that specific size.
The classic mass-market paperback. Standard for romance, thriller, mystery, and high-volume genre fiction.
Slightly wider than mass market. A comfortable middle ground for fiction that wants more page presence.
The most popular indie publishing size. Works for virtually every genre, balances readability and cost.
The default for nonfiction, literary fiction, and longer works. Feels substantial, reduces page count.
Full letter size for workbooks, textbooks, cookbooks, and any book with wide content like tables or images.
Larger type for readers who need it. A growing market with specific conventions for trim, font size, and spacing.
How to choose
If you're publishing fiction and aren't sure, start with 5.5" × 8.5". It's the most versatile size, works for every genre, and produces a professional-looking book at a reasonable printing cost.
If you want to match the mass-market paperback feel that genre readers expect, go with 5" × 8".
For nonfiction, 6" × 9" is the default. It gives you room for wider content and looks more substantial on a shelf.
Use our KDP Book Calculator to plug in your word count and see exact page counts, spine width, and printing costs for any trim size.
Know your trim size?
Format the book.
Cambric applies the correct margins, fonts, and page layout for your chosen trim size automatically. Pick a template and export.