How KDP printing costs work

The model in one line

printing cost = fixed charge + (pages × per-page charge)

Both numbers come from a table, and the table is selected by four things: the marketplace you are selling in, whether the book is paperback or hardcover, the ink and paper combination, and whether your trim size is standard or large.

Within a table the charges are banded by page count. Short books fall into a band with a flat fixed charge and no per-page component at all — which is why a 40-page book and a 100-page book often cost the same to print. Past the band threshold the fixed charge drops and each page starts adding to the total.

That structure has a consequence worth internalising: cost per page is not constant, and the cheapest place to be is right at the top of the flat band. Adding ten pages to a 105-page book costs real money; adding ten to a 70-page book usually costs nothing.

Where the royalty comes in

KDP applies your royalty rate to the list price and then subtracts the printing cost. For print books the rate is 60% at or above a per-marketplace threshold and 50% below it.

Because the rate applies to the whole price, the threshold creates a step rather than a slope. Pricing just below it can leave you with less per copy than pricing just above it, even though the reader pays less — the rate drop outweighs the price cut. Each marketplace page below shows where that step sits in its own currency.

The printing cost also sets a hard floor: KDP will not accept a price at which a sale would produce a negative royalty. On a long or colour book that floor can be high enough to price the book out of its own category, which is a structural problem rather than a pricing one.