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Ask ten Amazon sellers how their ads are doing and most will answer with one number: ACOS. It is the metric Amazon puts in front of you in the advertising console, and it is useful. But on its own it can lead you to cut campaigns that are growing your business, or to keep campaigns that are only buying sales you would have made anyway.
TACOS fills that gap. This guide explains both metrics, how to calculate them, what a “good” number looks like and how we use them together when we manage Amazon PPC for our clients.
What is ACOS?
ACOS (Advertising Cost of Sales) is your ad spend divided by the sales Amazon attributes to those ads.
ACOS = ad spend ÷ ad-attributed sales × 100
If you spend $300 on a campaign and it generates $1,000 in attributed sales, your ACOS is 30%. Every $1 of ad-driven sales cost you 30 cents in advertising.
ACOS answers one question well: how efficient is this campaign, keyword or product target? It is the right metric for day-to-day optimization: raising or lowering bids, adding negative keywords and moving budget between campaigns.
ROAS (return on ad spend) is the same information turned upside down: ad-attributed sales divided by ad spend. A 30% ACOS equals a ROAS of about 3.3.
What is TACOS?
TACOS (Total Advertising Cost of Sales) is your ad spend divided by your total sales, both ad-driven and organic.
TACOS = ad spend ÷ total sales × 100
If you spend $300 on ads in a month and the product sells $5,000 in total, your TACOS is 6%.
TACOS answers a different question: how much does advertising cost relative to the whole business, and is that changing over time? It is the metric for monthly reviews and for deciding how much to invest in a product overall.
Why ACOS alone can mislead you
On Amazon, advertising and organic rank feed each other. Ads bring sales, sales help organic rank, and better organic rank brings more sales without ad spend. ACOS only sees the first step.
Two common situations show the problem:
- A launch campaign with high ACOS. A new product might run at 60% ACOS for its first weeks. On ACOS alone, that looks like a campaign to cut. But if organic sales are rising and TACOS is falling month after month, the ads are doing their job: building the rank that will carry the product later.
- A low-ACOS campaign that adds nothing. A campaign bidding only on your own brand name might show a 5% ACOS. It looks excellent, but many of those shoppers were already looking for you and might have bought anyway. If total sales stay flat while ad spend grows, TACOS rises and the campaign is mostly paying for sales you already had.
How to read ACOS and TACOS together
The useful signal is how the two move relative to each other over several weeks:
- ACOS stable, TACOS falling: healthy growth. Organic sales are growing faster than ad spend.
- ACOS rising, TACOS falling: often fine during a launch or a push for rank, as long as the trend in organic sales continues.
- ACOS falling, TACOS rising: campaigns look efficient, but the business is leaning more heavily on ads. Check whether organic sales are slipping, for example because of lost rank, a weaker listing or stock problems.
- Both rising: ads are getting more expensive and organic sales are not keeping up. Time for a full review of bids, targets, listing quality and pricing.
What is a good ACOS?
There is no universal good ACOS. The number that matters is your break-even ACOS: your profit margin per unit before advertising, as a percentage of the price.
Break-even ACOS = (price − product cost − Amazon fees − other variable costs) ÷ price × 100
If a product sells for $40 and leaves $14 after product cost and Amazon fees, its break-even ACOS is 35%. Below 35%, the ad-driven sale is profitable; above it, you lose money on that sale, although you may still choose to accept that during a launch.
From there, set a target ACOS per product based on its goal:
- Launch or rank push: at or even above break-even for a limited period, if TACOS and organic rank are moving the right way.
- Mature best-seller: well below break-even, to protect profit.
- Clearance: whatever moves the stock before storage fees rise.
Break-even ACOS changes whenever your price, costs or Amazon fees change. Amazon’s 2027 fee update is a good example; our guide to the 2027 FBA fee changes explains what to recalculate.
What is a good TACOS?
Again, it depends on margin and stage. Many established brands aim for TACOS in the single digits or low teens, while a product in launch can run much higher for a while. More useful than any benchmark is the trend for each product: for a product you are not actively launching, a steady or falling TACOS is usually a good sign.
Three practical tips
- Measure TACOS by product, not only for the whole account. An account-level TACOS can hide one product that relies heavily on ads behind another that sells mostly organically.
- Mind attribution windows. Amazon credits Sponsored Products sales within 7 days of a click and Sponsored Brands and Sponsored Display sales within 14 days. Recent days always look worse than they will end up, so avoid judging a campaign on the last two or three days.
- Look at weeks, not days. Daily ACOS and TACOS are noisy. Weekly figures show the real direction.
How we use these metrics
We review ACOS by campaign, keyword and product to optimize bids and targets, and TACOS and organic sales by product to decide where to invest. In PataraWeb 2.0, our analytics app, ad spend, ad-driven sales, organic sales and profitability sit side by side, so both views are available in one place, and we review them with our clients every week. If you would like us to look at your account, get in touch.
FAQ
What is the difference between ACOS and TACOS?
ACOS is ad spend divided by ad-attributed sales. TACOS is ad spend divided by total sales, ad-driven and organic. ACOS measures campaign efficiency; TACOS measures the effect of advertising on the whole business.
Is a lower ACOS always better?
No. A very low ACOS can mean you are bidding too cautiously and missing profitable sales, or advertising mainly to shoppers who would have bought anyway. Compare ACOS with your break-even ACOS and watch TACOS and total sales.
How do I calculate break-even ACOS?
Take your price, subtract product cost, Amazon fees and other variable costs, and divide the result by the price. That percentage is the highest ACOS at which an ad-driven sale still breaks even.
Where can I find TACOS in Seller Central?
Amazon does not show TACOS as a single figure in most reports. You calculate it by combining ad spend from the Amazon Ads console with total sales from Seller Central’s Business Reports, or use a tool that brings both together.
