Royalty per copy at your price, break-even ACOS, the most you can pay per click, and what is left after Amazon Ads. No sign-up, nothing you enter leaves your browser.
How many sales and what BSR your goal takes — the AuthorLens BSR calculator →
Stop doing this math by hand every week
AuthorLens shows these numbers for every book from your real KDP and Amazon Ads data — no spreadsheets.
Open AuthorLensRoyalty per copy is what Amazon pays you after taking its share and the printing cost. This is your real income from a sale, not the price of the book.
Break-even ACOS is the key number on this page. It is the ad spend share at which you make zero. If your ACOS is higher, every book you sell loses money, even when the report shows sales growing. This is where new authors burn their budget: they watch the number of orders and ignore this threshold.
Sales to your goal is how many copies you need to sell each month to reach your net profit target after ad costs.
Organic sales are sales without ads. They keep the full royalty, and that changes the whole math: the bigger your organic share, the higher the ACOS you can afford. At 30% organic, your break-even ACOS grows about 1.4 times, at 50% it doubles. You still need ads for organic sales to appear at all: Amazon is more willing to show a book that already has sales and reviews. A healthy book gets 30–50% organic.
Max cost per click is break-even ACOS × list price × conversion rate — the same as royalty times conversion rate. At 10%, one sale takes ten clicks, so those ten clicks together can't cost more than the royalty on one copy. For a $24.99 black-and-white 8.5×11 paperback ($12.15 royalty) that's $1.22 per click. Organic sales aren't counted here — they give you extra room.
The calculator does not include taxes, returns or different royalty terms across marketplaces. It shows the economics of one book, not your whole business.
AuthorLens, an analytics tool for Amazon KDP, calculates the same numbers from your real sales: royalties, ad spend, organic sales and net profit for every book, across all 23 Amazon marketplaces. We use AuthorLens daily and have a business relationship with it.
Open AuthorLensTake two numbers for the same month: royalties from KDP and ad spend from Amazon Ads. Neither report shows what is left — this does.
Prefilled with our real December 2025: three books, $3,070.48 in royalties, $1,510.64 on ads, ACOS 22.13%. Replace them with yours.
Paperback. Amazon pays 60% of the list price minus printing costs when the book is priced at $9.99 or more, and 50% below that. The formula from KDP Help (as of September 2026): “(Royalty rate x list price) – printing costs = royalty”.
Example: a color 8.5×11 book with 75 pages priced at $24.99. Printing costs $4.02, and the royalty is $10.98 per copy in the KDP royalty calculator.
eBook. 70% of the list price without VAT minus delivery costs when the price is between $2.99 and $12.99, and 35% outside that range (KDP Help, as of September 2026).
Royalty is not profit yet: your ads are paid out of it. How much you can spend on ads and how many copies you need to sell to hit your goal is what the calculator above shows. If your book is in Kindle Unlimited or part of a series, use the break-even ACOS calculator for books: it adds page reads and sales of the next books.
60% of the list price minus printing costs at $9.99 and above, 50% below $9.99. For example, a color 8.5×11 book with 75 pages at $24.99: printing $4.02, royalty $10.98 per copy.
You don't have to: choose the store, interior, trim size and page count, and the calculator works out printing cost from KDP's tables, the same way KDP's own royalty calculator does. Before publishing you can double-check it at kdp.amazon.com/royalty-calculator.
70% of the list price without VAT minus delivery costs ($0.15 per MB on Amazon.com) when the price is between $2.99 and $12.99, otherwise 35% with no delivery cost. In the calculator, choose Kindle eBook and enter your file size.
The share of ad spend in sales at which a book breaks even. It equals royalty divided by list price. If your campaign ACOS is higher, every copy sold through ads loses money.
No more than your royalty times your conversion rate. At a 10% conversion rate one sale takes ten clicks, so for a $24.99 black-and-white 8.5×11 paperback with a $12.15 royalty the limit is $1.22 per click. The calculator shows it for your numbers.
ACOS divides ad spend by ad-attributed sales at list price. KDP pays you a royalty, a fraction of that price. So ACOS 22% can mean ads took about half of what KDP paid: in our December 2025, $1,510.64 on ads against $3,070.48 in royalties.
Monthly: subtract your Amazon Ads spend from your KDP royalties for the same month — the block above does it for you. Per book and per marketplace, AuthorLens (authorlens.remskill.com) pulls both automatically. We use AuthorLens daily and have a business relationship with it.
In the US, UK, the EU stores (Germany, France, Spain, Italy, Netherlands, Ireland, Belgium), Poland and Sweden. Five trim sizes: 5.5 × 8.5, 6 × 9, 6.14 × 9.21, 7 × 10 and 8.25 × 11 inches, from 75 to 550 pages. Interior is black and white (white or cream paper) or premium color — KDP has no standard color for hardcovers. For Canada, KDP's own calculator prices hardcovers like Amazon.com, in US dollars.
In Australia KDP prints paperbacks only, in black and white or premium color; there is no standard color and no hardcover. Japan has paperbacks with every interior but no hardcover. That is what KDP Help and KDP's own royalty calculator show (checked September 26, 2026).
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