ACoS (Advertising Cost of Sale) is the percentage of ad revenue you spend on Amazon ads. The formula is ad spend divided by ad revenue, times 100. Spend $200 on ads that generate $1,000 in sales and your ACoS is 20%. A good ACoS is any figure below your break-even ACoS, which equals your profit margin.
TL;DR
- ACoS = ad spend / ad revenue x 100. Lower means more efficient ad spend.
- Break-even ACoS = your profit margin. Below it you profit; above it you lose money on that ad sale.
- ACoS vs TACoS: ACoS measures ad efficiency alone; TACoS measures ad spend against your total revenue, showing whole-business impact.
- A "good" ACoS is 15 to 30% for most sellers, but launch campaigns can run 40% or higher on purpose to buy ranking.
- Keeping ACoS profitable means constant bid and keyword tuning, which is why many sellers automate it with an operator instead of watching dashboards daily.
What is ACoS on Amazon?
ACoS is the ratio of what you spend on ads to what those ads earn, expressed as a percentage. It answers one question: for every dollar of ad-driven sales, how many cents went to advertising? A 25% ACoS means 25 cents of every ad-sales dollar paid for the ad.
The formula is simple:
ACoS = (Ad spend / Ad revenue) x 100
An example makes it concrete. If you spend $150 on Sponsored Products and those ads drive $600 in sales, your ACoS is 25%. That $600 counts only sales Amazon attributes to the ad, usually purchases within a set window after a click.
ACoS is the most-watched Amazon advertising metric because it directly ties spend to return. According to Amazon Ads, sponsored ads are the primary way most sellers drive discoverability, and ACoS is how you know whether that spend is efficient. If you're new to the wider system, our complete Amazon PPC guide covers the campaign types that generate this spend.
How do you calculate ACoS?
Calculate ACoS by dividing your ad spend by the ad revenue it generated, then multiplying by 100. Both numbers come straight from your Amazon Advertising reports, so no complex math is needed. The nuance is understanding what each number includes.
- Ad spend: total clicks paid for in a campaign or account over a period.
- Ad revenue: sales Amazon attributes to those ads, within the attribution window.
Here is ACoS at different spend and revenue levels:
| Ad spend | Ad revenue | ACoS | ROAS |
|---|---|---|---|
| $100 | $1,000 | 10% | 10.0x |
| $200 | $1,000 | 20% | 5.0x |
| $300 | $1,000 | 30% | 3.3x |
| $500 | $1,000 | 50% | 2.0x |
Note the inverse relationship with ROAS (Return on Ad Spend), which is ad revenue divided by ad spend. A 20% ACoS is a 5x ROAS. They describe the same thing from opposite directions, so use whichever you find clearer.
What is a good ACoS on Amazon?
A good ACoS is any figure below your break-even ACoS, which equals your profit margin. There is no universal "good" number, because a 30% ACoS is excellent for a high-margin product and ruinous for a thin-margin one. Your margin sets the line.
That said, here are rough benchmarks sellers use as reference points:
| ACoS range | Interpretation | Typical use |
|---|---|---|
| Under 15% | Very efficient | Mature, high-margin products |
| 15 to 30% | Healthy for most | Steady-state selling |
| 30 to 40% | Break-even zone for many | Watch closely |
| Over 40% | Losing money unless launching | Launch or ranking pushes |
According to the Jungle Scout State of the Amazon Seller Report, advertising is one of the top challenges sellers cite, and much of that difficulty is judging what ACoS to accept. The answer is always relative to margin and stage, never an absolute target you copy from someone else.
What is break-even ACoS?
Break-even ACoS is the point where an ad sale earns zero profit, and it equals your profit margin before advertising costs. Above it, each ad sale loses money. Below it, each ad sale earns money. This single number turns ACoS from an abstract percentage into a clear profit-or-loss line.
To calculate it:
- Start with your selling price.
- Subtract product cost, Amazon referral and FBA fees, and shipping.
- Divide what's left by the selling price.
- That percentage is both your profit margin and your break-even ACoS.
For example, a product sells for $30. Product cost is $8, Amazon fees are $9, shipping is $2. That leaves $11 profit, or a 36.7% margin. So your break-even ACoS is roughly 37%. Any ad sale under 37% ACoS profits; anything over loses money.
This is why sellers with different products chase wildly different ACoS targets. A supplement with 50% margins can happily run a 40% ACoS. A commodity with 20% margins cannot survive above 20%.
What is the difference between ACoS and TACoS?
ACoS measures ad spend against ad revenue only. TACoS measures ad spend against your total revenue, including organic sales. ACoS tells you if a campaign is efficient; TACoS tells you if advertising is growing your entire business.
The formulas:
- ACoS = Ad spend / Ad revenue x 100
- TACoS = Ad spend / Total revenue x 100
Why you need both: ACoS can look bad while your business thrives. Imagine a campaign at 40% ACoS that drives sales velocity, which lifts your organic ranking, which grows organic sales. Your ACoS stays 40%, but your TACoS falls because total revenue is climbing faster than ad spend. Cutting that "expensive" campaign on ACoS alone would kill the organic growth it was fueling.
| Scenario | ACoS | TACoS | What it means |
|---|---|---|---|
| Healthy growth | 30% | 8% and falling | Ads are lifting organic sales |
| Ad-dependent | 30% | 25% and flat | Sales rely heavily on ads |
| Warning sign | 30% | Rising | Spending more for the same total |
A falling TACoS over time is one of the best signals in Amazon advertising. It means your ad dollars are building organic momentum, not just renting sales. Track it monthly alongside ACoS. Our Amazon PPC strategy for 2026 guide shows how to use both to steer scaling decisions.
When should you accept a high ACoS?
Accept a high ACoS when you are launching a product or pushing for organic ranking, because you are buying visibility rather than immediate profit. A high ACoS is not automatically bad. During a launch, it is a deliberate investment in sales velocity that Amazon's algorithm rewards with better organic placement.
Situations where a higher ACoS makes sense:
- Product launch: no ranking history means ads are your only visibility. Expect 40%+ ACoS for a few weeks.
- Ranking push: driving a key keyword to page one, where the long-term organic sales outweigh the short-term ad loss.
- Inventory clearance: moving aging stock before long-term storage fees hit.
- Brand defense: protecting your own branded searches, which is cheap insurance against competitors.
Amazon Ads notes that sales velocity and conversion feed organic ranking, which is the mechanism that makes launch-phase overspending pay off. The mistake is running a high ACoS forever with no plan to tighten it once ranking is earned.
How do you lower your Amazon ACoS?
Lower ACoS by cutting wasted spend, improving conversion, and moving budget to proven keywords. There are two levers: spend less on what does not convert, or convert more of what you already spend on. Both pull ACoS down.
Quick wins:
- Add negative keywords to stop paying for searches that never sell.
- Cut bids on keywords running above your target ACoS.
- Improve your listing so more clicks become sales. Better conversion lowers ACoS with no bid change at all.
- Harvest winners into exact-match campaigns for tighter control.
- Fix your main image and price, the two biggest conversion levers.
The conversion point is underrated. If your listing converts at 8% instead of 5%, your ACoS drops sharply without touching a single bid, because the same ad spend produces more sales. For a full playbook, see how to lower ACoS.
Retail media competition keeps rising, with eMarketer projecting US retail media ad spend past $100 billion and Amazon holding the largest share, which pushes costs per click up over time. That makes ACoS discipline more important each year, not less.
Frequently asked questions
What is ACoS on Amazon?
ACoS (Advertising Cost of Sale) is the percentage of your ad revenue spent on advertising. The formula is ad spend divided by ad revenue, times 100. If you spend $200 on ads that generate $1,000 in sales, your ACoS is 20%. Lower ACoS means more efficient ad spend.
What is a good ACoS on Amazon?
A good ACoS is any figure below your break-even ACoS, which equals your profit margin. Many sellers target 15 to 30%. During a launch, a higher ACoS of 40% or more is acceptable because you are buying ranking. The right number depends entirely on your margins.
What is the difference between ACoS and TACoS?
ACoS measures ad spend against ad revenue only. TACoS measures ad spend against total revenue, including organic sales. ACoS shows campaign efficiency; TACoS shows whether ads are growing your whole business. A falling TACoS means ads are lifting organic sales.
How do I calculate break-even ACoS?
Break-even ACoS equals your profit margin before advertising costs. Take your selling price, subtract product cost, Amazon fees, and shipping, then divide the result by the selling price. If your margin is 35%, your break-even ACoS is 35%. Below that you profit; above it you lose money per ad sale.
Is a low ACoS always good?
Not always. A very low ACoS can mean you are underspending and missing sales and ranking. During a launch, an intentionally high ACoS builds organic rank that pays off later. Judge ACoS against your margin and your stage, not as a number to minimize at all costs.
How do I lower my Amazon ACoS?
Lower ACoS by adding negative keywords, cutting bids on terms above target, improving your listing conversion rate, and moving winners into exact-match campaigns. Better conversion lowers ACoS without touching bids, because more clicks turn into sales.
Knowing your ACoS is easy. Keeping it profitable every day is the hard part. Jinnify manages your bids and keywords as an operator, steering ACoS toward your target and cutting waste automatically, so you get profitable ads without living in Amazon Advertising. Start for free with a 7-day trial, no card required.
Author: The Jinnify Team - Amazon growth and automation specialists Published: 2026-07-08 | Updated: 2026-07-08 Sources: Amazon Ads, Jungle Scout State of the Amazon Seller Report, eMarketer