Amazon Advertising Metrics: ACoS, TACoS, ROAS, CTR, CVR & NTB
Every optimization decision you’ll ever make starts by reading a number correctly. Here are the ones that matter, the formulas behind them, and what “good” actually looks like.
Amazon advertising metrics split into two families: engagement metrics (impressions, clicks, CTR, CPC, CVR) that show how your ad and listing are performing, and efficiency metrics (ACoS, ROAS, TACoS, NTB) that show whether the spend is worth it. ACoS — ad spend divided by ad sales — is the headline number most sellers optimize first.
01The two families of metrics
It’s easy to drown in the dozens of columns Amazon reports. Almost all of them fall into two buckets. Engagement metrics describe the journey — how many people saw the ad, clicked it, and bought. Efficiency metrics describe the economics — how much that journey cost relative to what it earned. You diagnose problems with the first family and judge profitability with the second. Keep that split in mind and the numbers stop feeling like noise.
02The engagement metrics
These five tell you where a campaign is winning or losing:
- Impressions — how many times your ad was shown. Low impressions usually mean a low bid or a tiny audience.
- Clicks — how many times it was clicked.
- CTR (click-through rate) = clicks ÷ impressions. Measures how compelling your main image, title, and price are in the search results. Weak CTR is usually a creative or relevance problem.
- CPC (cost per click) = spend ÷ clicks. The actual average price you paid per click — driven by competition and your bids.
- CVR (conversion rate) = orders ÷ clicks. Measures how well your listing converts the traffic. Weak CVR points at the product page, not the ad.
This split is diagnostic gold: a low CTR is an ad problem, a low CVR is a listing problem. They need different fixes.
03ACoS — the core efficiency number
ACoS (Advertising Cost of Sale) = ad spend ÷ ad sales, shown as a percentage. If you spent $20 to make $100 in ad sales, your ACoS is 20%. Lower means more efficient. It’s the number most sellers watch daily because it directly answers “am I making money on these ads?” What counts as good depends entirely on your margins — a 25% ACoS is great for a high-margin product and a disaster for a thin one. The ACoS vs TACoS deep dive covers target-setting properly.
04ROAS — the same truth, flipped
ROAS (Return on Ad Spend) = ad sales ÷ ad spend, shown as a multiple. That $20-for-$100 example is a 5× ROAS. ROAS and ACoS are two views of the same relationship: ROAS = 1 ÷ ACoS. A 20% ACoS is a 5× ROAS; a 50% ACoS is a 2× ROAS. Amazon sellers tend to speak in ACoS, while advertisers from Google or Meta backgrounds prefer ROAS — pick one and stay consistent so your team doesn’t talk past each other.
05TACoS — the whole-business number
TACoS (Total ACoS) = ad spend ÷ total sales, where total sales includes both advertising and organic. This is the metric that connects back to the flywheel. If your ad spend holds steady but your TACoS falls over time, it means organic sales are growing — your ads are lifting the whole business, not just buying sales one click at a time. A rising TACoS on flat spend is an early warning that you’re becoming dependent on ads. It’s the single best health metric for a product’s long-term trajectory.
06New-to-Brand (NTB)
NTB metrics flag orders from customers who haven’t bought your brand in the past year — new customers, not repeat buyers. They matter most for upper-funnel formats like Sponsored Brands, Sponsored TV, and DSP, where the goal is acquisition rather than harvesting existing demand. A campaign with a mediocre ACoS but a high NTB share can still be a win, because you’re buying customers, not just sales. Judging those formats on ACoS alone undervalues them.
07Turning metrics into decisions
Numbers only matter if they change what you do. The anchor is your break-even ACoS, which equals your profit margin before ad cost. If a product carries a 35% margin, a 35% ACoS breaks even — anything below is profit, anything above is a loss you’re choosing to accept (which can be smart during a launch to build rank). From there: a low CTR sends you to the creative, a low CVR sends you to the listing, and a high CPC sends you to your bids. Every metric points at a specific lever. For the advanced, cross-channel view of how these connect, Amazon Marketing Cloud goes deeper than the standard reports can.
08Formula reference
Bookmark this — every core metric in one place:
| Metric | Formula | What it tells you |
|---|---|---|
| CTR | clicks ÷ impressions | How compelling the ad is in search results |
| CPC | spend ÷ clicks | Average price you paid per click |
| CVR | orders ÷ clicks | How well the listing converts traffic |
| ACoS | ad spend ÷ ad sales | Ad efficiency — lower is better |
| ROAS | ad sales ÷ ad spend | Return per $1 spent — higher is better |
| TACoS | ad spend ÷ total sales | Ads’ impact on the whole business |
| NTB % | new-to-brand orders ÷ total orders | Share of sales from new customers |
| Break-even ACoS | = profit margin | The ACoS where you neither profit nor lose |
- Engagement metrics (CTR, CPC, CVR) diagnose problems; efficiency metrics (ACoS, ROAS, TACoS, NTB) judge profit.
- Low CTR = ad/creative problem. Low CVR = listing problem. Different fixes.
- ACoS and ROAS are the same relationship flipped: ROAS = 1 ÷ ACoS.
- Falling TACoS on steady spend means organic sales are growing — the flywheel working.
- Your break-even ACoS equals your margin; NTB rewards acquisition that ACoS alone misses.
Frequently asked questions
What is a good ACoS on Amazon?
There’s no universal number — a good ACoS is anything below your break-even ACoS, which equals your profit margin. A 25% ACoS is excellent on a high-margin product and unprofitable on a thin one. During a launch, sellers often accept a higher ACoS on purpose to build rank.
What’s the difference between ACoS and TACoS?
ACoS divides ad spend by ad sales only, so it measures the efficiency of the ads themselves. TACoS divides ad spend by total sales (ads plus organic), so it measures how ads are affecting your entire business. A falling TACoS signals healthy organic growth.
What is ROAS on Amazon?
ROAS (Return on Ad Spend) is ad sales divided by ad spend, expressed as a multiple. A 4× ROAS means you earned four dollars of ad sales for every dollar spent. It’s the inverse of ACoS: ROAS = 1 ÷ ACoS.
How is ACoS calculated?
ACoS = ad spend ÷ ad sales, shown as a percentage. If you spent $30 and generated $120 in ad-attributed sales, your ACoS is 25%.
What does New-to-Brand (NTB) mean?
NTB metrics measure orders from shoppers who haven’t purchased your brand in the previous twelve months. A high NTB share means your advertising is acquiring new customers rather than just capturing repeat buyers, which is the main goal of upper-funnel formats.
Or head back to the full Amazon Advertising course hub.