Book Royalty Calculator: KDP vs IngramSpark vs Draft2Digital (Exact Math)

The numbers don't lie — but the platforms sure make it confusing.

If you've spent any time researching self publishing services, you've probably hit a wall of vague percentages and marketing language that tells you very little about what you'll actually take home. So let's cut through it. This is a straight-up royalty breakdown, real math, real scenarios, so you can make an informed decision before you publish a single page.

Most first-time authors focus on cover design, editing, and launch strategy. Royalties? That's an afterthought. But if you're publishing a $14.99 paperback and choosing the wrong platform, you could be leaving anywhere from $1.50 to $4.00 per sale on the table. Multiply that by a few hundred copies, and the difference becomes very real, very fast.

At Berg Publishers, we walk authors through this math before they commit to any platform because the "best" book publishing service isn't universal. It depends on your trim size, page count, price point, and distribution goals. Two authors selling the same-priced book can walk away with completely different royalty checks based solely on which platform they chose.

Below is how each major platform calculates what you actually earn — using the same reference book so the numbers are apples to apples.

KDP is the most popular entry point for self-published authors, and for good reason: it's free, fast, and gives you direct access to the world's largest book retailer.

KDP pays 60% of your list price, minus the printing cost.

Printing cost formula: Fixed cost + (per-page cost × page count)

For a standard 6×9 black-and-white paperback (let's say 250 pages):

Fixed cost: $0.85

Per page: $0.012

Print cost: $0.85 + (250 × $0.012) = $3.85

On a $14.99 book:

$14.99 × 60% = $8.99 → $8.99 − $3.85 = $5.14 royalty

That's solid. But KDP's ecosystem is largely Amazon-only unless you opt into Expanded Distribution, which drops your royalty rate and gives you far less control over pricing at other retailers. For authors whose entire audience lives on Amazon, KDP is arguably the most efficient self publishing service available. For everyone else, it's just the starting point.

IngramSpark is the go-to for authors who want wide distribution in bookstores, libraries, academic channels, and international markets. It's the backbone of many professional book publishing services and the preferred route for authors who want their titles sitting on physical shelves, not just Amazon product pages.

IngramSpark works on a wholesale discount model. You set the retail price and choose a wholesale discount (typically 40–55% for broad retailer access). Your royalty is what's left after the discount and print cost.

Using the same 250-page 6×9 paperback at $14.99 with a 40% wholesale discount:

Retail: $14.99

Wholesale discount (40%): −$6.00

Subtotal: $8.99

Print cost (IngramSpark, same trim): ~$4.05

Royalty: ~$4.94

Slightly lower than KDP direct, but you're getting into Barnes & Noble, Books-A-Million, and thousands of independent bookstores. For authors building a long-term brand, that reach is worth the trade-off.

One thing to note: IngramSpark has setup fees (though they run periodic waivers), and the interface has a steeper learning curve than KDP. If you're new to self publishing, having a service like Berg Publishers guide the setup process can save you from costly formatting and metadata errors that delay your launch.

Draft2Digital is the underdog that doesn't get enough credit. It's primarily an eBook aggregator, but it also handles print distribution through a partnership with IngramSpark's network.

D2D takes 10% of the retail price as its cut. So on a $4.99 eBook:

Retailer keeps ~30% (varies by store)

Remaining 70%: $3.49

D2D takes 10%: −$0.35

Your royalty: ~$3.14

Compare that to KDP's 70% direct royalty on the same $4.99 eBook:

$4.99 × 70% = $3.49

KDP wins on per-unit eBook royalties when selling through Amazon. But D2D gets your book onto Apple Books, Barnes & Noble Nook, Kobo, Scribd, and a dozen other platforms simultaneously — something KDP Select explicitly prohibits. If your readers aren't Amazon loyalists, D2D's reach more than compensates for the slightly smaller cut.

D2D's print royalties mirror IngramSpark's numbers closely, since they use the same print network. Expect to see roughly the same $4.50–$5.20 range on a standard paperback, depending on page count and price.

Here's what Berg Publishers recommends to most of our authors: don't pick one platform — combine them strategically.

Publish your print book on KDP for Amazon sales and set up a separate IngramSpark listing for everything else. For eBooks, skip KDP Select (which locks you into Amazon exclusivity) and distribute widely through Draft2Digital. Yes, your per-unit Amazon eBook royalty drops slightly, but your overall revenue ceiling expands dramatically.

This hybrid approach does require a bit more management; you'll be tracking sales across multiple dashboards and ensuring your metadata stays consistent across platforms. But it's the same strategy that professional self publishing services use for authors who are serious about building readership across multiple channels. More platforms mean more discoverability, and discoverability is what turns a good book into a sustainable income stream.

The other advantage nobody talks about: platform diversification protects you. If Amazon changes its royalty structure tomorrow (and it has before), authors who went wide aren't scrambling.

KDP offers the highest per-unit royalties for Amazon sales — 60% of list price minus print cost for paperbacks, 70% for eBooks priced $2.99–$9.99. IngramSpark suits wide retail and library distribution. Draft2Digital distributes eBooks across 10+ platforms for a 10% fee. For maximum earnings, combine all three rather than choosing one exclusively.