KDP raised its printing costs again in 2026, and most indie authors are leaving money on the table because they don’t understand how trim size, font choice, and margin width compound into per-unit cost. The difference between a well-optimized interior and a carelessly formatted one can be $0.50-$1.00 per copy — which, across a thousand sales, is your next cover design budget.
Let’s do the math.
How KDP calculates printing cost
KDP’s printing cost formula is straightforward: a fixed cost plus a per-page charge. For a standard black-and-white paperback in the US marketplace as of early 2026:
- Fixed cost: $0.85 per copy
- Per-page cost: $0.012 per page
So a 300-page paperback costs $0.85 + (300 x $0.012) = $4.45 to print. A 260-page version of the same book costs $0.85 + (260 x $0.012) = $3.97 to print. That 40-page difference is $0.48 per copy.
These numbers come directly from Amazon’s KDP printing cost page. Check the current rates before you finalize — they’ve adjusted them three times since 2023.
Font choice: 15-20 pages you didn’t know you were paying for
Here’s where most authors lose money without realizing it. Different fonts at the same point size produce dramatically different page counts because of how wide or narrow the characters run.
Take a 75,000-word novel set at 11pt with 1.4x line spacing on a 5.5” x 8.5” page:
| Font | Approximate pages | Printing cost |
|---|---|---|
| Garamond | ~270 | $4.09 |
| Caslon | ~280 | $4.21 |
| Baskerville | ~285 | $4.27 |
| Palatino | ~290 | $4.33 |
Garamond runs about 15-20 pages shorter than Palatino at the same settings. That’s a $0.24 per-copy difference in printing cost — purely from font choice. Multiply by 2,000 copies and you’ve saved $480 without changing a single word.
This doesn’t mean Garamond is always the right choice. Palatino is a beautiful font, and those wider letterforms improve readability for some readers. But you should make that trade-off consciously, knowing what it costs. Cambric lets you switch fonts and see the page count change in the live preview — so you can evaluate the aesthetic and economic trade-off before committing. Our guide to the best fonts for self-published books breaks down when each font makes sense.
Trim size: the biggest lever you have
Trim size affects page count more than any other variable. The same 75,000-word manuscript produces wildly different page counts depending on how big the page is:
| Trim size | Approximate pages | Printing cost | Reader expectation |
|---|---|---|---|
| 5” x 8” | ~340 | $4.93 | Romance, thriller, mystery |
| 5.25” x 8” | ~310 | $4.57 | Genre fiction (slightly roomier) |
| 5.5” x 8.5” | ~280 | $4.21 | Literary fiction, memoir, SFF |
| 6” x 9” | ~230 | $3.61 | Non-fiction, epic fantasy |
The difference between 5” x 8” and 6” x 9” is $1.32 per copy. That’s significant. But you can’t just pick the cheapest option — readers have genre expectations about book size, and violating them makes your book feel wrong in their hands. A romance novel printed at 6” x 9” looks amateurish regardless of how good the interior is. For a deeper dive, see our complete guide to KDP trim sizes.
The royalty math that actually matters
Let’s put it all together. You’ve priced your paperback at $14.99 and you’re selling on Amazon. KDP pays a 60% royalty on the list price minus printing cost.
Configuration A: 5” x 8”, Palatino, generous margins
- Page count: ~350
- Printing cost: $5.05
- Royalty: ($14.99 x 0.60) - $5.05 = $8.99 - $5.05 = $3.94
Configuration B: 5.5” x 8.5”, Garamond, standard margins
- Page count: ~270
- Printing cost: $4.09
- Royalty: ($14.99 x 0.60) - $4.09 = $8.99 - $4.09 = $4.90
Same book. Same price. Same content. $0.96 more per copy just from smarter formatting decisions. At 500 copies, that’s $480. At 2,000 copies, it’s $1,920.
You can run your own numbers with Cambric’s KDP book calculator — plug in your word count, pick your trim size and font, and see the actual royalty.
The margin trade-off
Wide margins look undeniably professional. Traditional publishers often use generous margins — 0.75” or more on the outside, 0.875” or more on the gutter side. That whitespace gives the page room to breathe and signals quality.
But wider margins push text onto more pages. Increasing your outside margins from 0.625” to 0.875” on a 5.5” x 8.5” book can add 20-30 pages. That’s $0.24-$0.36 per copy.
The sweet spot for most indie authors is margins that meet KDP’s minimums with a small buffer: 0.625”-0.75” outside, 0.375” + gutter on the inside (KDP requires additional gutter for thicker books — check their specifications for the exact formula). This produces a clean, professional look without inflating page count.
What to actually do
Here’s the practical takeaway:
- Run the numbers before you finalize your interior. Use a word count tool to get your exact count, then calculate printing cost at two or three configurations.
- Pick trim size for your genre first, then optimize within it. Don’t fight reader expectations to save $0.30.
- Try Garamond or Caslon before defaulting to wider fonts. The page count savings are real, and both are beautiful book fonts.
- Set margins to “professional but not extravagant.” Meet the minimums with a comfortable buffer, not an inch of whitespace on every side.
Cambric makes this experimentation painless — switch between fonts, trim sizes, and margin settings and see the page count update in the live preview before you export. You can literally watch your printing cost change as you adjust settings. That feedback loop is how you find the configuration that balances aesthetics and economics for your specific book.
The formatting decisions you make aren’t just about how your book looks. They’re about how much you earn per copy, every single time someone buys it. Do the math.