Calculate ACOS, TACOS and your break-even point using ad sales, organic sales, royalties and the KENP income that may arrive later.
| Metric | Result | How to read it |
|---|---|---|
| ACOS | — | Ad spend ÷ ad-attributed sales |
| TACOS | — | Ad spend ÷ total sales revenue |
| Break-even ACOS | — | Royalty per sale ÷ book price |
| ACOS headroom | — | Break-even ACOS minus current ACOS |
| Maximum break-even spend | — | Maximum spend supported by attributed sales royalties |
| Sales needed to cover spend | — | Ad spend ÷ royalty per sale |
| Net contribution | — | Entered royalties and KENP minus ad spend |
Shows how much of the ad-attributed sales revenue is being spent on ads. Compare it with break-even ACOS.
Includes organic sales. A campaign can have a high ACOS while the whole book business has a healthier TACOS.
KENP income can arrive later. Reconcile the same period again after the KDP report is settled.
Advertising reports and Kindle Unlimited page-read income do not always arrive at the same time. That means a single week's ACOS can look worse than the eventual contribution from the same book. Enter KENP separately, compare settled periods, and avoid treating delayed income as an immediate campaign result.
A $9.99 book earning $6.49 royalty per sale has a basic break-even ACOS of about 65%. If Amazon Ads reports $50 spend and $150 attributed sales, Console ACOS is 33.3%, leaving roughly 31.7 percentage points of headroom before direct attributed royalties are consumed.
If the same period also produces organic sales or settled KENP income, those amounts improve the broader net contribution—but they should not be used to disguise an ad campaign that repeatedly exceeds its direct break-even guardrail.
What is break-even ACOS?
It is the maximum ad spend as a percentage of ad-attributed sales before the royalty from those sales is fully consumed by advertising spend.
Should I track TACOS as well as ACOS?
Yes. TACOS includes organic sales and helps you see whether advertising is supporting the whole book business.
Should I include KENP in break-even ACOS?
Use the basic break-even ACOS as the guardrail. Treat KENP as a separate, delayed income line and reconcile it after the period settles.
Does this connect to Amazon?
No. It runs in your browser and only uses the numbers you enter from your own reports.
KDP Royalty Calculator — estimate royalty per sale before checking ad profitability.
KENP Calculator — estimate page-read income at the current rate.
KDP Print Cost Calculator — calculate paperback printing cost before pricing.
KDP Ads Budget Calculator — estimate clicks, sales needed and a daily test budget before launching a campaign.
KDP Ads VAT/GST Calculator — see your true ACOS after invoice tax and regulatory fees.
KDP Calc Pro — future saved scenarios and reporting features.
Estimates only — verify royalties, ad attribution and KENP income against your KDP and Amazon Ads reports. This is not financial advice.