Free tools

Calculators for anyone publishing a book. They run in your browser — no signup, no email, nothing stored.

Amazon moved its royalty band in July 2026 and a lot of the calculators you will find still use the old one. These are checked against Amazon's own pages every week.

• KDP royalty calculator

  What Amazon actually pays you per sale, on both royalty options, across all nine marketplaces.

  Amazon raised the 70% ceiling to $12.99 in July 2026. Calculators still using the old $9.99 will understate anything you price above $10.

  Checked 30 August 2026

• KDP cover calculator

  Spine width and the full flat cover for a paperback, in inches, millimetres and pixels at 300 DPI.

  Bleed is included rather than left as an exercise, and it says when Amazon will refuse to print spine text at all — under 80 pages, however thick the artwork makes the spine look.

  Checked 30 August 2026