Amazon ACOS: What It Is and 6 Practical Ways to Lower It (2026)

Short answer: ACOS (advertising cost of sales) is your ad spend divided by the sales those ads generate: ACOS = (ad spend ÷ ad revenue) × 100. According to Amazon Ads, to stay profitable your ACOS needs to be lower than your profit margin. The main ways to lower it: add non-converting search terms as negatives, move converting terms into manual campaigns with bids set against your profit target, and make sure the product page you advertise is ready to convert.

Amazon Ads' own guide says there isn't a definitive number for a good ACOS; it depends on industry, company size and campaign setup. So your target is your own margin, not someone else's average. The six methods below apply to Sponsored Products.

Know your target first: break-even ACOS

Break-even ACOS equals your profit margin before ad spend. Below it, ad-driven sales make money; above it, they lose money. ROAS is the inverse of ACOS (ad revenue ÷ ad spend).

Example (formula illustration only): with a 30% pre-ad profit margin, break-even ACOS is 30% and break-even ROAS is about 3.33 (1 ÷ 0.30). Any ACOS below 30% leaves profit on ad-driven sales.

To run your own numbers, use the ACOS and break-even ad calculator, and the Amazon FBA profit calculator to find your pre-ad margin.

1. Add negatives from the search-term report

The search-term report shows the shopper searches that led to at least one click on your ad. Review it regularly for your automatic and broad-match campaigns, and add irrelevant or non-converting terms as negative keywords.

Don't rush: Amazon Ads suggests evaluating a term after it has received at least 20 clicks, and letting negative keywords run for two weeks or more before changing your strategy. Negatives aren't permanent; you can remove them.

2. Move from automatic to manual

With automatic targeting, Amazon matches your ad to relevant searches; with manual targeting, you choose the keywords, bids and match types. Amazon Ads recommends running both, and letting an automatic campaign run for about two weeks before creating a manual one.

Add the search terms that drive sales to a manual campaign as exact match, where you control bids per keyword. A structure that works in practice: automatic (discovery) → phrase (expansion) → exact (control).

3. Set bids against break-even ACOS

Compare each keyword's ACOS with your break-even level: raise bids on converting keywords below it, lower them on those above it. Amazon's bidding strategies help: "dynamic bids - down only", "dynamic bids - up and down", and "fixed bids", which use the exact bid you enter. Data-driven bidding, not a blind "increase the budget".

4. Group winners in their own campaign

Look at which keywords your sales concentrate in on the search-term report. Put them in a separate, tightly managed campaign so budget doesn't scatter to irrelevant searches and you can control their bids on their own.

5. Fix the listing; ads can't save it

ACOS's apparent cause is the ads; the real cause is often the product page. Amazon Ads' best-practices guide recommends that advertised products have:

• The Featured Offer, and stock available
• Four or more high-quality, zoomable images (at least 1,000 pixels)
• At least three bullet points
• Five or more customer reviews with a rating of 3.5 stars or higher

Pouring ad spend into a page that doesn't convert is carrying water in a leaky bucket. Listing optimization first, budget second. To tighten the title, try the Amazon title generator.

6. Watch TACOS, not just ACOS

Ads can affect organic sales too. TACOS is total ad spend divided by total sales (ad plus organic); it isn't an official metric in Amazon's ACOS guide but a ratio sellers commonly use. Tolerating near-break-even ACOS on a keyword can make sense if total sales grow and TACOS holds up. Track both ratios together.

FAQ

What is ACOS and how is it calculated? It's ad spend divided by the sales those ads generate: (ad spend ÷ ad revenue) × 100. For example (formula illustration only), $100 of spend producing $400 of ad revenue is a 25% ACOS.

What is a good ACOS? Amazon Ads says there isn't a definitive number. The yardstick is your own margin: if ACOS is below your pre-ad profit margin, the ads are profitable.

How do I find my break-even ACOS? It equals your profit margin before ad spend. At a 30% margin, break-even ACOS is 30% (example only).

What's the difference between ACOS and ROAS? ROAS is the inverse of ACOS: ad revenue ÷ ad spend. A 25% ACOS equals a ROAS of 4.

How long should I wait before adding negative keywords? Amazon Ads suggests waiting until a term has at least 20 clicks, and letting negatives run for two weeks or more before changing course.

The takeaway

Lowering ACOS is the sum of a margin-based target, negative-keyword discipline, the right campaign structure, data-driven bidding and, most often skipped, product-page quality. How long results take depends on the product, category and competition.

To have us run your ad account against a profit target, there's Amazon PPC management; for the whole account, Amazon consulting. The full ad framework is in the e-commerce advertising guide.

Sources and scope

• Amazon Ads, ACOS: Advertising cost of sales: definition and formula, break-even ACOS vs. profit margin, ROAS as the inverse of ACOS, no definitive "good ACOS"
• Amazon Ads, A guide to targeting with Sponsored Products: automatic vs. manual targeting, match types, negative keywords, 20-click and two-week guidance
• Amazon Ads, Sponsored Products best practices: search-term report, exact-match recommendation, bidding strategies, product-page readiness
• Amazon Ads, Sponsored Products: cost-per-click model and eligibility

Example calculations illustrate the formula only and are not industry averages. This article is general information; Amazon Ads options change, so check the ad console and official pages for current details. Information checked on October 14, 2026.