Key Takeaways
- ACoS is ad spend divided by ad sales. Spend $500 to get $2,000 in ad-attributed sales and your advertising cost of sales (ACoS) is 25%.
- Your break-even ACoS is the only benchmark that counts. It equals your profit margin before advertising, so a product that keeps 30% of its price after costs and fees breaks even at a 30% ACoS.
- A good ACoS depends on the job the campaign is doing. Launch, brand defense, profitable scaling and clearing stock each deserve a different target, and sometimes a different success metric.
- Watch TACoS next to ACoS. Total advertising cost of sales shows whether ads are growing the whole business or just buying sales you would have made anyway.
- Conversion rate is the biggest lever. A listing that converts better lowers ACoS at the same bids, which is why listing work often beats bid work.
A good ACoS on Amazon is any ACoS below your break-even ACoS, which equals your product's profit margin before ad spend. If a product keeps 30% of its selling price after cost of goods, Amazon fees and shipping, anything under 30% ACoS is profitable on the ad sale. Whether you should run above or below that line depends on the campaign's job: launching, defending, scaling or clearing stock.
If you have spent any time in Seller Central, you have seen the ACoS column and wondered whether your number is good, bad or leaving money on the table. Most brands react to that number without a framework for what it should be. This guide gives you the framework: how to calculate ACoS, how to find your own break-even, when a high ACoS is the right call, and what actually lowers it without killing sales.
What is ACoS on Amazon?
ACoS stands for advertising cost of sales. It is Amazon Ads' core efficiency metric for Sponsored Products, Sponsored Brands and Sponsored Display campaigns. It tells you what share of ad-attributed revenue you spent on advertising to get it. For definitions of the other terms in this guide, see our Amazon PPC glossary.
How do you calculate ACoS?
ACoS = (ad spend / ad-attributed sales) x 100
If you spent $500 on ads and those ads were credited with $2,000 in sales, your ACoS is 25%. If you spent $25 and got $100 in ad sales, it is also 25%. The math is simple. The interpretation is where brands go wrong, because that same 25% can be excellent for one product and a loss for another.
What does ACoS leave out?
ACoS only counts sales Amazon attributes to an ad click within its attribution window. It does not count organic sales, most repeat purchases, or sales that happen after the window closes. It also changes after the fact: Amazon keeps crediting conversions to recent days for a while, so the last few days in any report usually look worse than they will once the data settles. Two practical rules follow:
- Judge campaigns on weekly or two-week trends, not yesterday's number.
- Never judge ACoS alone. Pair it with TACoS and organic rank, covered below.
How do ACoS, TACoS and ROAS compare?
| Metric | Formula | What it tells you | Best used for |
|---|---|---|---|
| ACoS (advertising cost of sales) | Ad spend / ad-attributed sales x 100 | How efficiently ad clicks turn into ad sales | Campaign, keyword and target decisions |
| TACoS (total advertising cost of sales) | Ad spend / total sales x 100 | How much of the whole business goes to ads | Brand health and ad dependency |
| ROAS (return on ad spend) | Ad-attributed sales / ad spend | The same thing as ACoS, flipped into a multiple | Comparing with Google, Meta or TikTok ads |
ROAS is the inverse of ACoS: a 25% ACoS is a 4.0 ROAS, and a 50% ACoS is a 2.0 ROAS. Some agencies report only ROAS because a bigger number reads better. Ask to see ACoS and TACoS as well.
How do you find your break-even ACoS?
Your break-even ACoS is the ACoS at which an ad-driven sale makes exactly zero profit. It equals your profit margin before advertising.
Break-even ACoS = (selling price minus all costs except ads) / selling price x 100
"All costs" means cost of goods, inbound freight, the Amazon referral fee, the FBA (Fulfillment by Amazon) fulfillment fee or your own shipping cost if you use FBM (fulfilled by merchant), storage, and an allowance for returns. Below break-even, the ad sale is profitable. Above it, you are paying for something other than immediate profit: rank, reviews, reach or cleared inventory. Our break-even ACoS calculator works this out from your own price, costs and fees.
What does break-even ACoS look like in practice?
Here is a worked example with made-up round numbers, not benchmarks. Use your own.
| Line | Product A | Product B |
|---|---|---|
| Selling price | $40.00 | $40.00 |
| Cost of goods and freight | $8.00 | $18.00 |
| Referral fee, fulfillment and other Amazon fees | $12.00 | $12.00 |
| Profit before ads | $20.00 | $10.00 |
| Break-even ACoS | 50% | 25% |
| Result at a 30% ACoS | Profitable | Losing money on each ad sale |
Same price, same ACoS, opposite outcomes. That is why a single "good ACoS" number from a blog post, including this one, cannot tell you whether your campaigns work. It is also why ACoS should be judged against contribution margin, not revenue alone.
Why don't we publish an average ACoS by category?
Category averages float around the internet, but they mix products with very different margins, prices and repeat rates, and they rarely say where the data came from. A 25% ACoS in a category means nothing if your product's break-even is 18%. Start from your own break-even, then set a target below it based on the campaign's job.
How should manufacturers and Vendor Central brands calculate it?
If you sell to Amazon wholesale through Vendor Central (1P, or first party), your ads are credited with sales at Amazon's retail price, but you are paid the wholesale price. Calculate break-even on the retail price the ads report against: (wholesale price minus your costs) / retail price. A brand that computes margin on the wholesale price will set its break-even too high and overspend. Brands selling through Seller Central (3P, or third party) use their own selling price, as in the table above.
CPG, food and beverage, and retail-first brands have a second question: does Amazon advertising lift sales elsewhere? Some shoppers see the product on Amazon and buy it in a store or on your site. That lift does not show up in ACoS. If you believe it is real, measure it (for example, by region or by comparing periods) before using it to justify a higher target.
What is a good ACoS for each campaign goal?
A good ACoS depends on what you asked the campaign to do. We set the posture first, then the target, and sometimes the posture changes the success metric itself.
| Campaign goal | ACoS target relative to break-even | What success looks like |
|---|---|---|
| Launch | Above break-even, for a set period and budget | Sales velocity, reviews and organic rank on target keywords |
| Brand defense | Usually well below break-even | Competitors kept off your brand searches and listings |
| Category growth | Near break-even | New keywords won, total sales and organic rank rising |
| Competitor conquesting | Often above break-even | Share taken on searches you do not own yet |
| Profit focus | Clearly below break-even | Profit dollars after ad spend |
| Clearing inventory | May ignore break-even | Units sold and aged stock gone before storage costs rise |
Using one ACoS target across branded, category and competitor campaigns is one of the most common mistakes we see. Segment the targets by campaign type and intent.
When is a high ACoS the right call?
- Product launches. Early on you are buying sales velocity, reviews and ranking data, not immediate profit. Set a time limit and a budget cap before you start, and track organic rank so you know when the investment is paying back.
- High lifetime value products. If buyers reorder, subscribe through Subscribe and Save, or buy other items from you, the first sale can lose money and the customer can still be profitable. Model lifetime value before calling an ACoS "too high".
- Market share plays. When a competitor pulls back, a short period of heavier spend can win rank that holds after the campaign ends.
- Seasonal peaks. Prime Day, Q4 and category peaks bring more buyers and higher cost per click (CPC). Some brands accept a higher ACoS in those windows because the volume is there.
When is a low ACoS a warning sign?
A very low ACoS often means the account only advertises on its own brand name and a few exact match keywords. Those clicks convert well, but many of those shoppers were already looking for you. You are paying for sales you would have made anyway and not reaching new customers. A low ACoS is only good if total sales and organic rank are growing too. If they are flat, bids may be too timid to win the searches that matter.
Why does TACoS matter more than ACoS for brand health?
TACoS = (total ad spend / total sales) x 100
TACoS measures ad spend against all sales, organic included, so it shows how dependent the business is on advertising. Take ad spend from the advertising console and total sales from Business Reports in Seller Central (or your vendor reports), and track it monthly. Weekly TACoS is noisy.
A worked example: you spend $1,000 on ads, those ads are credited with $4,000 in sales, and total sales for the month are $10,000. ACoS is 25%. TACoS is 10%. The other $6,000 came from organic search, repeat buyers and brand searches, some of which the ads helped create.
How do you read ACoS and TACoS together?
| ACoS trend | TACoS trend | What it usually means |
|---|---|---|
| Rising | Flat or falling | Ads are pushing into new searches and organic sales are growing. Often healthy. |
| Falling | Rising | Ad efficiency is up but organic sales are shrinking. Check rank, reviews and stock. |
| Rising | Rising | Spend is growing faster than the business. Check structure, bids and conversion. |
| Falling | Falling | Ads and organic are both improving. Consider reinvesting in growth. |
How does ad spend build organic rank?
Ads drive clicks and sales on target keywords. Those sales tell Amazon's ranking system the product is relevant and converts, which tends to lift organic rank. Organic rank brings sales you do not pay for, so total sales grow faster than ad spend and TACoS falls. That frees budget for new keywords or products, and the cycle starts again. It is also why a product's overall profit matters more than the ACoS on one campaign: if ads are a small share of an ASIN's sales and the ASIN is profitable overall, a high ACoS on one campaign may be fine.
The flip side: cutting bids to improve ACoS can also cut organic rank, and the organic sales you lose can be worth far more than the ad spend you saved. Watch organic rank and total sales whenever you pull bids down. For more on this, read TACoS vs ACoS: which metric to manage to.
Not sure what your ACoS should be? Book a free 30-minute strategy call. We will look at your margins, your campaign structure and your TACoS trend, and tell you where spend is leaking and what we would change first.
How can you lower ACoS without killing sales?
"Lower your bids" is the usual advice, and on its own it usually shrinks sales along with ACoS. These steps, in this order, tend to lower ACoS while protecting volume.
- Know your numbers. Map true margin, break-even ACoS, a target ACoS for each campaign goal, and lifetime value where repeat buying is real.
- Fix the listing first. ACoS is driven by CPC and conversion rate. If your listing converts at half the rate of competitors, no bid strategy closes that gap.
- Split campaigns by intent. Separate discovery, proven keywords, competitor targets and brand defense so you can see where spend goes.
- Harvest and add negatives every week. Move converting search terms into exact match and block the ones that spend without converting.
- Adjust bids by placement and time. Bid where your product converts and pull back where it does not.
- Give changes time. Measure over weeks, not days, and change one thing at a time where you can.
How should campaigns be structured to control spend?
- Auto campaigns: discovery only, with modest bids and budgets. Mine the search term report weekly.
- Broad and phrase match campaigns: a second discovery layer.
- Exact match campaigns: proven keywords. This is where most of the budget and most of the optimization belong.
- Competitor targeting campaigns: a separate budget, judged on their own results.
- Brand defense campaigns: your brand terms only. Do not let them run out of budget.
Accounts with runaway ACoS often have everything in one or two auto campaigns with no harvesting, so they pay discovery prices for clicks that belong in tight exact match campaigns. Our Amazon PPC advertising hub covers structure in more depth, and Amazon PPC: the complete guide for brands walks through each campaign type.
Which search terms should become negative keywords?
Pull search term reports every week. When a term has had enough clicks that it should have converted and has not, add it as a negative. Common candidates:
- Competitor brand names, unless they sit in a dedicated competitor campaign with its own budget.
- Research searches such as "how to" or "what is".
- Sizes, colors or variants you do not sell.
- Related but wrong products that attract clicks and never convert.
How do placement and dayparting affect ACoS?
Amazon's placement reports show whether top of search, rest of search and product page placements convert at different rates. If one placement converts much better, adjust placement bid modifiers instead of raising every base bid. Dayparting, adjusting bids by hour and day, helps when your own hourly conversion data shows clear weak windows. Look at at least several weeks of data before acting, because a single week can mislead.
Why does listing quality move ACoS more than bids?
More sales from the same clicks means a lower ACoS at the same bids. Before touching bids, check:
- The main image, which drives click-through from search results.
- A title that leads with the product type and main keyword.
- Bullets that answer buyer objections, not just list features.
- A+ Content that builds trust and cross-sells.
- Enough reviews to earn trust before heavy spend.
- Price and in-stock status. Out-of-stock variants and lost Buy Box both hurt conversion.
See our Amazon listing optimization hub for the listing side.
What ACoS mistakes cost brands the most?
- One target for every campaign. Brand, category and competitor campaigns need different targets.
- Killing campaigns too early. A new campaign needs enough clicks to show a pattern. Look at trends, not snapshots.
- Judging on revenue, not margin. Two $50 products with different costs have different break-evens.
- Reacting to the last few days. Recent attribution is still filling in. Daily changes on daily data chase noise.
- Forgetting organic rank. Saving a few points of ACoS is a bad trade if organic sales fall.
When should a brand get help with ACoS?
Not every brand needs outside help. These signs say the account has outgrown how it is being run:
- ACoS has sat above break-even for months with no plan to bring it down.
- Nobody reviews search term reports weekly.
- The account is all auto campaigns or one catch-all manual campaign.
- Ad spend rises month over month while total sales do not.
- TACoS has been climbing for more than a quarter.
- No one can tell you the break-even ACoS of your top products.
Good PPC management starts with an audit of margins, goals and structure before changing a bid, reports on TACoS, organic rank and profit rather than ACoS alone, and works on listings and ads together. If you want a second opinion first, here is what to check in an Amazon account audit. For how rising click costs change the math, read the CPC crisis and Amazon profitability.
Frequently Asked Questions
What is a good ACoS on Amazon?
A good ACoS is one below your break-even ACoS, which equals your profit margin before advertising. A product that keeps 30% of its price after costs and fees is profitable on ads below a 30% ACoS. During a launch or a market share push, running above break-even for a planned period can be the right choice.
How do I calculate ACoS on Amazon?
Divide ad spend by ad-attributed sales and multiply by 100. If you spent $1,000 and those ads were credited with $4,000 in sales, your ACoS is 25%. Both numbers are in the Amazon Ads campaign manager reports.
How do I calculate my break-even ACoS?
Subtract every cost except advertising from your selling price, including cost of goods, freight, referral fee, fulfillment and returns, then divide by the selling price. That percentage is your break-even ACoS. Vendor Central brands should divide their profit per unit by the retail price, because ad sales are reported at retail.
Is 30% ACoS good?
It depends on your margin. With a 50% margin before ads, a 30% ACoS is comfortably profitable. With a 20% margin, a 30% ACoS loses money on every ad sale unless the campaign has a deliberate goal such as a launch.
What is the difference between ACoS and TACoS?
ACoS measures ad spend against ad-attributed sales only. TACoS measures ad spend against total sales, including organic. A rising ACoS with a flat or falling TACoS usually means ads are helping organic sales grow.
Should I pause campaigns with a high ACoS?
Not automatically. First check whether the campaign is new and still gathering data, whether it has a strategic job such as a launch or brand defense, and what happened to organic rank and total sales while it ran. Pause or restructure when it is above break-even with no goal behind it.