Find your break-even ACOS, target ACOS, and maximum profitable bid in seconds. Works for eBooks, paperbacks, and series authors.
Series authors can advertise at a higher ACOS because each reader is worth multiple book royalties.
Royalty per Sale
70% of $4.99
Break-Even ACOS
Advertising at this ACOS = $0 profit
Target ACOS
65% of break-even — leaves a profit margin
Max Profitable Bid (CPC)
At 10% conversion × target ACOS
What This Means
You can run ads at up to 70.0% ACOS and still break even. Set your target at 45.5% to maintain a healthy margin, and bid up to $0.35 per click.
Set your book price and royalty rate. For eBooks priced $2.99–$9.99 in KDP Select, use 70%. For paperbacks, enter your print cost to get the accurate net royalty.
If you write a series, enter the number of books and your estimated read-through rate. This dramatically increases your "value per reader" and allows a higher target ACOS.
Set your Amazon Advertising target ACOS to the calculated value. Use the max bid as your starting bid for new keywords, then adjust based on actual performance data.
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