Amazon Book Sales Calculator
Paste any book’s Best Sellers Rank and get an estimate of how many copies it sells per day and month — with Amazon’s KDP royalty math applied, so you can size up a niche before you write into it.
The rank shown on the book’s Amazon page under “Product details” (Kindle Store).
Royalty math follows Amazon’s published KDP rules: 70% inside the eligible price band (minus the per-MB delivery fee), 35% outside it.
Rank-to-sales curves are community estimates and vary by category and season — treat these as an order of magnitude, not a forecast. Track your real numbers with AuthorLens →
How the estimate works
Amazon doesn’t publish sales numbers, so no calculator can measure them — including this one. We interpolate over rank-to-sales anchor points the KDP author community has assembled from thousands of self-reported sales/rank pairs, on a log-log curve (rank 1 moves thousands of copies a day; rank 1,000,000 moves a copy every few days). Non-US marketplaces are scaled by relative store size.
Royalties use Amazon’s published KDP rules: eBooks earn 70% inside the eligible price band (minus a per-megabyte delivery fee) or 35% outside it; paperbacks and hardcovers earn 60% of list price minus printing cost.
Real sales vary by category, season, reviews and Kindle Unlimited share — treat the output as an order of magnitude. When it’s your own book, you don’t need estimates: AuthorLens tracks your real royalties and ad spend and shows true net profit per title.