Free tool

KDP True Profit Calculator

What a title actually earns once Amazon Ads and marketing are paid for — and the break-even ACOS that decides whether a campaign is worth running at all. Nothing is sent anywhere; the arithmetic happens in this page.

Your title

Format

Only used to label your result. The arithmetic is the same for every format.

List price

Royalty per sale

Both figures come from KDP when you set your price. This page does not work out your royalty rate, because it varies by marketplace, format and price band.

Units sold in the period

Kindle Unlimited page-read royalties — optional

The money, not the pages. Amazon sets the per-page rate after the month closes, so this figure only exists once the month has ended.

What you spent

Amazon Ads spend

Other marketing

Newsletter features, promo graphics, anything you paid for to sell this title.

Conversion rate — optional

Orders ÷ clicks, as a percentage, from your Amazon Ads report. Only needed for break-even CPC.

Your numbers

Sales royalties: enter royalty per sale and units sold
Page-read royalties: optional
Total royalties: —
Total marketing spend: enter ad spend
Marketing as a share of royalties: —
Net after marketing: —

Break-even

Break-even ACOS: enter list price and royalty per sale
Break-even CPC: enter royalty per sale and conversion rate

Above the break-even ACOS, a campaign spends more than the royalties it earns. Below it, the campaign pays for itself on attributed sales alone.

Two numbers that are not the same number

Amazon Ads ACOS

ad spend ÷ Amazon Ads attributed sales

Attributed sales are the retail price of the books Amazon believes your ad sold. It is the number the Ads console shows you, and it is measured against money you never receive.

Your actual economics

royalties earned − marketing spend

What reaches you is the royalty, which is a fraction of the retail price. The point where the two meet is break-even ACOS = royalty ÷ list price.

A worked example. A £4.99 ebook returning a £3.42 royalty breaks even at a 68.5% ACOS. A £14.99 paperback returning £3.59 breaks even at 24.0%. The same 60% ACOS is comfortable on the first and ruinous on the second — which is why a single "good ACOS" number passed around in forums is worth very little.

Break-even ACOS is a floor, not a verdict. It cannot see Kindle Unlimited pages your ad caused, later books in a series the same reader went on to buy, or sales Amazon did not attribute. All three make the real break-even point higher. Treat a figure above it as a reason to look, not as proof a campaign has failed.

Managing more than one book?

Publisher Command Center

This page answers the question for one title in one period. The Command Center holds your whole catalogue: every title, what stage it is at, what each one cost, what each one earned, every campaign measured against its own break-even ACOS, a launch pipeline and a release gate.

Books · Launches · Ads · Economics · Marketing

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