Advertising on Amazon can sell books and can lose money quietly, and the number that tells the difference is the ACOS, the advertising cost of sales. It is the share of the sales from your ads that you spent on the ads. If you spent 120 dollars and the ads brought 260 dollars in sales, your ACOS is about 46 percent. Whether that is good depends on how much of each sale you keep, which for an author is the royalty and not the price.
Amazon Ads ACOS Calculator that shows whether your Amazon ads pay for themselves
The amazon ads acos calculator works out your advertising cost of sales, your break-even ACOS from your royalty and price, your cost per click, your conversion rate, your cost per order and your profit on direct sales, using your ad spend, sales, clicks and orders, with an optional line for the pages read that your ads drive in Kindle Unlimited. It runs in your browser and is free for authors who run Amazon Ads.
The amazon ads acos calculator is free to use, with no account and nothing uploaded.
- ACOS and break-even ACOS
- CPC and conversion
- Profit on direct sales
Key facts
- FreeNo cost, no account and no usage limit on the amazon ads acos calculator
- In your browserNothing that you type or paste into the amazon ads acos calculator is uploaded
- SecondsTypical time from opening the amazon ads acos calculator to a result
Amazon Ads ACOS calculator
Work out your ACOS, your break-even ACOS and your profit from Amazon Ads, using your spend, your sales and the royalty that you earn on each copy.
The amazon ads acos calculator needs JavaScript, and it works in your browser without sending anything that you enter to a server.
What the amazon ads acos calculator does and why it helps
That is why the break-even ACOS matters. It is your royalty per sale divided by the price, because that is the share of each sale you can spend on ads and still break even. A 4.99 dollar ebook at the 70 percent plan pays about 3.49 dollars, so the break-even ACOS is about 70 percent, and an ACOS below that means the ads are paying for themselves on direct sales alone. A 0.99 dollar book, or a paperback with a thin margin, has a much lower break-even.
The calculator also shows the other numbers that guide an ad campaign: the cost per click, the conversion rate from clicks to orders, the cost per order and the profit on direct sales. An ACOS above break-even is not always a failure. Ads for the first book in a series can pay for themselves through read-through to later books, and ads for Kindle Unlimited titles earn page reads that a sales-only calculation ignores. The tool gives you the direct numbers, and the context is yours to add.
The Amazon Ads ACOS calculator shows your advertising cost of sales, which tells you whether your ads are profitable. Authors can use this free amazon ads acos calculator as often as they like, and it never asks for payment. You can use the amazon ads acos calculator online in any modern browser, with nothing to install. It is an amazon ads acos calculator for authors, so the defaults assume you are preparing a book rather than a business report. Indie writers can rely on it as an amazon ads acos calculator for self-published books. Amazon authors can use it as an amazon ads acos calculator for KDP with no changes. There is no account to create, so this amazon ads acos calculator no sign up page is ready the moment it loads. We cannot say what the best amazon ads acos calculator is for everyone, but we have made this one show its working so you can trust the answer.
How to use the amazon ads acos calculator, step by step
Enter your ad spend
Type the total you spent on a campaign over the period you want to measure. Use the figure from your Amazon Ads dashboard for the same dates as your sales.
Enter your ad sales and orders
Add the sales revenue attributed to the campaign and the number of orders. The tool uses them to work out ACOS and cost per order.
Enter your clicks
Type the number of clicks, so that the tool can calculate your cost per click and your conversion rate from click to order.
Enter your royalty and price
Add the royalty you earn per sale and the price. The tool uses them to calculate your break-even ACOS, the level above which the ads lose money.
Add pages read if you use Kindle Unlimited
Add the pages your ads drive in Kindle Unlimited, if any, so that the tool counts that income as well as direct sales.
Read the verdict
Compare your ACOS with your break-even ACOS. If it is lower, the ads are profitable on direct sales, and if it is higher, adjust bids, keywords or the book page.
Spend, sales and the line between profit and loss
You enter your ad spend, the sales that the ads produced, the clicks and orders, the price of the book and your royalty per sale. The tool calculates ACOS, which is the spend divided by the sales, and the break-even ACOS, which is your royalty divided by the price.
It then compares the two. If your ACOS is lower than the break-even figure, direct sales more than pay for the ads. If it is higher, you lose money on direct sales, though that can still make sense if the ads lead readers into a series or into page reads. The tool also shows cost per click, conversion rate, cost per order and profit on direct sales.
A lower price changes the break-even point, because the royalty is a smaller share of the price, and an ad for a low-priced first-in-series book often runs at a loss to win a reader. Use the tool to set a target ACOS for each campaign and to decide when to pause one.
- ACOS and break-even ACOS side by side
- Cost per click, conversion and cost per order
- A plain verdict on direct sales
How the amazon ads acos calculator works out its answer
ACOS
Ad spend divided by the sales that came from those ads, shown as a percentage. It is the share of each ad-driven sale that went to advertising.
Break-even ACOS
Your royalty per sale divided by the book price. If your ACOS is lower than this, direct sales cover the cost of the ads.
Cost per click and conversion rate
Cost per click is spend divided by clicks. The conversion rate is orders divided by clicks, which shows how well your page turns visitors into buyers.
Profit on direct sales
Orders multiplied by your royalty per sale, minus the ad spend. It does not count read-through or page reads, which can add real value.
Getting the most from the amazon ads acos calculator
Know your break-even ACOS before you start
It sets the limit that any campaign must stay below to be profitable, and it guides every bid you set. The amazon ads acos calculator is free and instant, so it is worth running again whenever your book changes.
Compare cost per click and conversion rate
A low click cost with a poor conversion rate can still lose money, so look at both numbers together. Make the amazon ads acos calculator a routine step on every project, so that results stay consistent from book to book.
Review the numbers weekly
Keywords and competition change, so check regularly instead of leaving a campaign running unwatched. A few minutes with the amazon ads acos calculator now saves time across the whole manuscript.
When the amazon ads acos calculator is not enough
The calculator shows whether your ads pay. These services improve the things that make them pay: the cover, the page and the metadata behind every click.
Book Landing Page Design
A landing page can be the destination of your ads, and a fast, focused page raises the conversion rate and the value of every click.
See the service →Book Cover Design
A cover that stands out in search results lifts click-through, and a cover designer builds one for the thumbnail first.
See the service →Book Metadata Setup
Titles, keywords and categories decide where your book appears, and metadata setup tunes them for both organic search and ads.
See the service →Before and after using the amazon ads acos calculator
The same ad campaign, first judged by how many sales it brought and then by what each sale cost against the royalty.
- 1Ads running with no idea if they pay
- 2A break-even that was never worked out
- 3Bids set by feel
- 1An ACOS compared with a break-even
- 2A conversion rate that guides the page
- 3Bids set from a known limit
- 3problems found in the first review
- 3fixes checked in the final review
- 1named specialist owning every fix
- Fixedprice confirmed in the calculator before you order
Clarity
You know whether each campaign is profitable on direct sales, and which ones need a closer look.
Smarter bids
The break-even ACOS sets a ceiling for your bids, so you do not overpay for clicks.
A better page
The conversion rate tells you when the cover, blurb or price needs work, and not the ad.
What authors say about our advertising review service
Verified reviews from authors who asked a specialist to handle the advertising review after using the amazon ads acos calculator.
As a first-time author, the technical side of self-publishing was genuinely daunting. The consultation covered every decision — platform choice, pricing strategy, metadata, and distribution. I launched with genuine confidence.
Navigating IngramSpark's requirements for the first time felt overwhelming. The upload assistance handled everything — metadata, pricing setup, distribution channels. My children's book reached bookstores within two weeks.
My KDP file was rejected with a technical error message I could not understand. Book Formatting Experts diagnosed the problem immediately — a bleed issue on three pages — and corrected it the same day. Approved first time.
Getting historical fiction placed in the right categories on Amazon and IngramSpark required strategic metadata. The team understood the genre classification and the book reached the right readers from the first week.
The formatting error fix service saved my launch. My original formatter had made margin errors causing repeated rejection. Book Formatting Experts identified and fixed every issue within 48 hours. My launch was back on schedule.
My YA novel needed to reach both English-language and Japanese readers. The multi-region distribution setup was handled correctly across all required platforms. International sales have exceeded my expectations.
The publishing readiness review identified four issues in my manuscript that would have caused rejection. Each was clearly explained and quickly resolved. My book launched without any technical complications.
My cookbook needed to be set up across multiple platforms simultaneously. The publishing support team handled every submission — KDP, IngramSpark, and Apple Books — with different requirements for each. Flawlessly executed.
Good support throughout the KDP upload process. The metadata setup and category selection were explained clearly. One pricing setting needed adjustment after initial setup but it was corrected quickly.
Good publishing support overall. The KDP metadata setup was thorough. One category selection needed updating after initial launch but it was corrected promptly. The book is performing well in its target categories.
The 3D mockup of my hardcover looked so real that several readers asked where they could buy it before the book was even available. The render quality was exceptional and delivery was fast.
My spiritual book had Arabic quotations alongside English text. The bidirectional text layout was handled correctly and respectfully. The result reads clearly in both languages and the overall design is dignified.
My coaching workbook had exercises, worksheets, and reflection prompts alongside regular chapters. Every element was formatted to serve both digital completion and print. The result looks professional and functional.
Literary fiction covers require a completely different approach from genre fiction. The design is elegant, restrained, and communicates the literary quality of the book. I am genuinely proud to show it to readers.
My historical novel had period-appropriate chapter epigraphs and an author's note section. Every element was formatted with understanding of the genre's conventions. My literary agent commented on the professional quality.
My memoir needed a warm, readable layout with consistent chapter styling. The specialist understood exactly what I was after and the finished file exceeded my expectations on every page.
Every genre convention was applied correctly. The chapter openers, the dedication page, and the acknowledgements all flowed naturally. Readers have complimented how comfortable the book feels to read.
The tone of the design perfectly matched the warmth and humour of my books. Readers feel welcomed from the first page. My engagement metrics improved significantly within the first two weeks of the new site going live.
More free tools to use with the amazon ads acos calculator
Each of these tools is free, runs in your browser and works well alongside the amazon ads acos calculator.
Amazon Book Sales Calculator
Free amazon book sales calculator that works in your browser, plus a done-for-you sales review service.
Open the tool →KDP Royalty Calculator
Free kdp royalty calculator that works in your browser, plus a done-for-you KDP royalty review service in this advertising review order.
Open the tool →Book Pricing Calculator
Free book pricing calculator that works in your browser, plus a done-for-you pricing strategy review service with your advertising review.
Open the tool →Book Keyword Generator
Free book keyword generator that works in your browser, plus a done-for-you keyword research service.
Open the tool →ACX Royalty Calculator
Free acx royalty calculator that works in your browser, plus a done-for-you audiobook production service.
Open the tool →Audiobook Production Cost Calculator
Free audiobook production cost calculator that works in your browser, plus a done-for-you audiobook budget service for the advertising review.
Open the tool →Amazon Ads ACOS Calculator: questions answered
These are the questions authors ask most about the amazon ads acos calculator, including accuracy, privacy and what to do next. If your question about the advertising review is missing, request a quote and a specialist will reply.
What is an Amazon Ads ACOS calculator?
It is a tool that works out your advertising cost of sales, your break-even ACOS and your profit, from your ad spend, sales, clicks and royalty.
What does ACOS mean?
ACOS stands for advertising cost of sales. It is the ad spend divided by the sales that the ads brought, as a percentage.
What is a good ACOS for books?
It depends on your royalty. A good ACOS is below your break-even ACOS, which is your royalty divided by the price.
How do I work out my break-even ACOS?
Divide your royalty per sale by the book price. The calculator does this from the figures you enter.
Why is my break-even ACOS lower for paperbacks?
A paperback royalty is a smaller share of the price after printing cost, so the share you can spend on ads is smaller.
Is an ACOS above break-even always bad?
No. Ads for a first book in a series, or for a Kindle Unlimited title, may pay back through read-through and page reads.
What is a good conversion rate for a book ad?
It varies by genre and price. A rate of a few percent is common, and a low rate suggests that the cover, blurb or price needs work.
What is cost per click?
It is the amount you pay when a reader clicks your ad, calculated as spend divided by clicks.
Does the tool count page reads?
It lets you add pages read as context, but the profit figure counts direct sales only.
Where do I find my figures?
Your Amazon Ads dashboard shows spend, sales, clicks and orders, and your KDP reports show your royalty.
Does the amazon ads acos calculator keep anything that I enter?
No. The amazon ads acos calculator works in your browser, so what you enter stays on your device and is never saved.
Is the amazon ads acos calculator free?
Yes, the ACOS calculator costs nothing, needs no account and puts no limit on the campaigns you check.
How does an amazon ads acos calculator work?
It divides your ad spend by your ad-attributed sales to give ACOS, and compares it with your break-even ACOS.
How to use an amazon ads acos calculator?
Enter your ad spend, sales and royalty per sale, then read ACOS and break-even ACOS.
Is there an amazon ads acos calculator with examples?
Yes. The page includes a worked example so you can compare it with your own numbers or text. Try a campaign with spend and sales to see profit or loss.
What is the amazon ads acos calculator formula?
ACOS equals ad spend divided by ad sales, multiplied by one hundred.
Can I use a amazon ads acos calculator spreadsheet instead?
You can, and a amazon ads acos calculator spreadsheet works if you are happy to maintain the formulas yourself. This page does the maths for you and shows the working, so there is nothing to copy or update.
Turn what you learn from the amazon ads acos calculator into a finished book
The amazon ads acos calculator costs nothing, and so does asking what a specialist would do with your book. When the amazon ads acos calculator has done its part and you want finished files, a fixed price and one named person who owns the job, we are ready to start.
