About the KDP Ad Profit Calculator
Amazon's ad console reports sales and ACOS, but it never tells you whether a campaign is actually profitable for a book. That depends on your royalty, not the list price. A $14.99 paperback that pays you $4.99 per copy can show a respectable-looking ACOS and still lose money on every sale.
This calculator works the way book advertising actually behaves: you pay per click, a share of those clicks become orders, and each order pays you a royalty. Enter your price, royalty per sale, average cost per click, conversion rate and a budget, and it estimates clicks, sales, ad revenue, royalty earned and the resulting profit or loss. It also shows the three break-even numbers that matter most: the highest CPC you can pay, the lowest conversion rate you can survive, and the highest ACOS your royalty can absorb.
Use it to sanity-check a new campaign, decide whether a bid increase is affordable, or see how much a better cover or blurb (higher conversion) would change the outcome. If you do not know your royalty yet, find it first with the KDP Royalty Calculator.
How It Works
Clicks are your ad spend divided by your average CPC. Expected sales are clicks multiplied by your conversion rate. Revenue is sales multiplied by the book price, and royalty earned is sales multiplied by your royalty per sale.
Profit or loss is royalty earned minus ad spend. ACOS is ad spend divided by revenue, which is the figure Amazon shows in your ad reports.
The break-even figures come from the value of a single click. Each click is worth your royalty multiplied by your conversion rate. If your CPC is lower than that, each click makes money on average. The break-even conversion rate is your CPC divided by your royalty, and break-even ACOS is your royalty divided by your book price.
Formula
- Clicks
- Clicks = Ad spend ÷ Average CPC
- Sales
- Sales = Clicks × Conversion rate
- Profit
- Profit = (Sales × Royalty per sale) − Ad spend
- Break-even CPC
- Break-even CPC = Royalty per sale × Conversion rate
- Break-even conversion rate
- Break-even CR = Average CPC ÷ Royalty per sale
- Break-even ACOS
- Break-even ACOS = Royalty per sale ÷ Book price
Example
A $14.99 paperback earning $4.99 per sale, $200 budget, $0.40 CPC, 10% conversion
- Clicks: $200 ÷ $0.40 = 500 clicks.
- Sales: 500 × 10% = 50 sales.
- Revenue: 50 × $14.99 = $749.50. Royalty: 50 × $4.99 = $249.50.
- Profit: $249.50 − $200 = $49.50. ACOS: $200 ÷ $749.50 = 26.7%.
- Break-even CPC: $4.99 × 10% = $0.499. Break-even conversion rate: $0.40 ÷ $4.99 = 8.02%. Break-even ACOS: $4.99 ÷ $14.99 = 33.3%.
The campaign is profitable by about $49.50, keeping roughly $0.10 per click. Raising the average CPC above $0.50 or letting conversion fall below about 8% would turn it into a loss.
Important Notes
- Results are a simple average model. Real campaigns vary day to day, and small samples (a few hundred clicks) can swing conversion rate widely.
- Amazon attributes sales to ads within a set window after a click, so some reported sales may have happened anyway and some ad-influenced sales may not be counted.
- Kindle Unlimited page reads and read-through to other books in a series are not included. Both can make a campaign more profitable than this estimate shows.
- Royalty per sale should reflect the format being advertised. A paperback ad that mostly sells eBooks will behave differently.
- Taxes, currency conversion and other costs are not included.
Frequently Asked Questions
Why does the calculator use royalty instead of list price?
Because royalty is what you actually receive. Amazon reports ad sales at list price, but printing costs and Amazon's share come out before you are paid. A campaign is only profitable when royalty earned is greater than ad spend.
What is a break-even CPC?
It is the highest average cost per click you can pay without losing money. It equals your royalty per sale multiplied by your conversion rate. With a $4.99 royalty and a 10% conversion rate, each click is worth about $0.499 to you, so any average CPC below that is profitable.
Where do I find my conversion rate?
Divide orders by clicks in your Amazon Ads report for the same campaign and date range. The [Conversion Rate Calculator](/tools/conversion-rate-calculator) does this for you. Use at least a few hundred clicks of data so the rate is reasonably stable.
My campaign shows a loss here. Should I stop it?
Not automatically. This model ignores Kindle Unlimited reads and sales of later books in a series, which can make a loss-leading ad worthwhile. Look at your total royalties alongside ad spend with the [TACOS Calculator](/tools/tacos-calculator) before you decide.
What improves ad profit the most?
Usually conversion rate. Because every break-even number scales with conversion, a stronger cover, blurb, price or review count can turn an unprofitable campaign profitable without touching your bids.
Can I use this for Kindle eBook ads?
Yes. Enter the eBook list price and your eBook royalty per sale (for example 70% of the price minus delivery cost). The maths is the same for every format.
Related KDP Tools
- ACOS CalculatorCalculate Advertising Cost of Sale, plus break-even and target ACOS for books.
- Advertising Break-Even CalculatorFind your break-even CPC, break-even ACOS and maximum sustainable bid.
- ROAS CalculatorCalculate return on ad spend and convert it to ACOS.
- CPC CalculatorCalculate average cost per click from spend and clicks.
- Conversion Rate CalculatorCalculate the share of clicks or page visits that turn into orders.
- TACOS CalculatorMeasure ad spend against total sales, including organic, to see true ad dependency.
Related Guides
- How to Calculate KDP Ad Profit: ACOS, ROAS, CPC and Break-EvenCalculate whether your Amazon ads make money: ACOS, TACOS, ROAS, CPC, CPA, conversion rate, break-even ACOS and break-even CPC, with a worked example.
- How KDP Royalties WorkA clear guide to KDP royalties: the 35% and 70% eBook options, delivery costs and VAT, the 50% and 60% print tiers, expanded distribution and printing costs.