Amazon Ads ACOS Calculator

What is ACOS?

ACOS (Advertising Cost of Sale) measures how much you spend on advertising for every dollar of revenue generated. It is the most important metric for Amazon Ads because it directly tells you whether your ads are profitable.

ACOS Ranges for KDP Books

Break-Even ACOS Explained

Your break-even ACOS is the tipping point between profit and loss. It equals the percentage of revenue you keep after Amazon takes its cut and printing costs are deducted.

What is ACOS and how is it calculated?

ACOS (Advertising Cost of Sale) is the percentage of ad spend relative to the revenue generated from those ads. It is calculated as: ACOS = (Ad Spend / Ad Revenue) x 100. For example, if you spend $10 on ads and generate $50 in sales, your ACOS is 20%.

What is a good ACOS for KDP books?

A good ACOS for KDP books typically ranges from 30% to 50%, depending on your royalty rate and printing costs. The key metric is your break-even ACOS: as long as your ACOS is below your break-even point, your ads are profitable. For paperbacks with a 60% royalty, a 25-35% ACOS is generally strong.

What is break-even ACOS and why does it matter?

Break-even ACOS is the maximum ACOS you can sustain before losing money on ad-generated sales. It equals your royalty as a percentage of your list price. If your break-even ACOS is 40%, any ACOS above 40% means you are spending more on ads than you earn from those sales.

How do I lower my ACOS on Amazon Ads?

To lower your ACOS: (1) Refine your keywords by removing underperformers and adding negative keywords. (2) Lower bids on high-ACOS keywords. (3) Improve your book listing (cover, description, reviews) to boost conversion rate. (4) Use exact match keywords for proven winners. (5) Optimize your ad targeting to reach the right audience.

What is the difference between ACOS and ROAS?

ACOS and ROAS are inversely related. ACOS = Ad Spend / Revenue (expressed as a percentage), while ROAS = Revenue / Ad Spend (expressed as a multiplier). An ACOS of 25% equals a ROAS of 4x, meaning you earn $4 for every $1 spent. Lower ACOS and higher ROAS both indicate better ad performance.

Should I consider organic sales when evaluating ACOS?

Yes. Amazon Ads often create a "halo effect" where increased ad visibility boosts your organic ranking and sales. Your total ACOS (TACoS) may be significantly lower than your campaign ACOS because ads drive organic sales too. Many successful publishers accept a higher ACOS knowing the overall impact on their book sales is positive.

How much should I spend on Amazon Ads for my KDP book?

Start with $5-10 per day for a new campaign and run it for at least 2 weeks to gather meaningful data. Once you identify profitable keywords, gradually increase spend on winners. A common strategy is to allocate 10-20% of your expected monthly royalties to advertising, then scale based on profitability.

What is a good click-through rate (CTR) for Amazon book ads?

A good CTR for Amazon Sponsored Products ads on books is typically 0.3% to 0.5%. Above 0.5% is excellent. Low CTR usually means your book cover or ad targeting needs improvement. Your cover is essentially your ad creative on Amazon, so a professional cover directly impacts CTR.

How does conversion rate affect my ad profitability?

Conversion rate (orders divided by clicks) directly impacts profitability. A higher conversion rate means each click is more likely to turn into a sale, lowering your effective cost per acquisition. For KDP books, a 10-15% conversion rate on ads is considered good. Improve it with better book pages, more reviews, and competitive pricing.

What is Target ACOS and how should I use it?

Target ACOS is the ACOS you aim for to maintain a desired profit margin. Our calculator sets it at 70% of your break-even ACOS, providing a 30% profit margin on ad sales. Use your Target ACOS as a guide when setting bids and evaluating keyword performance. Keywords consistently above your Target ACOS may need lower bids or removal.