ACOS (Advertising Cost of Sale) is the most important metric in Amazon PPC advertising. It tells you exactly how much you are spending on ads for every dollar of revenue those ads generate.
The formula is straightforward:
ACOS = (Total Ad Spend ÷ Total Ad Revenue) × 100
For example:
Amazon reports ACOS at the campaign, ad group, and keyword level in Seller Central. It is the primary metric sellers use to evaluate whether their advertising is profitable.
Let's walk through two real-world scenarios to make the math clear.
Amazon calculates ACOS automatically in your campaign manager. But understanding the math helps you set bids and budgets more intelligently. For a more detailed look at managing ad costs, see our guide to reducing ACOS.
Is ACOS the same as ROAS? No — they are mathematically inverse. How is ACOS different from ROAS? ACOS is expressed as a percentage (spend ÷ revenue × 100), while ROAS is expressed as a ratio (revenue ÷ spend). They measure the same relationship from opposite directions.
ACOS and ROAS are two sides of the same coin.
| Metric | Formula | Expression | Example |
|---|---|---|---|
| ACOS | Spend ÷ Revenue × 100 | Percentage | 20% ACOS |
| ROAS | Revenue ÷ Spend | Ratio | 5:1 ROAS |
Key difference: ACOS looks at cost as a percentage of revenue. ROAS looks at revenue as a multiple of cost. A 20% ACOS means you earn $5 for every $1 spent — that is a 5:1 ROAS. They are mathematically interchangeable: ROAS = 1 ÷ ACOS (as a decimal).
Amazon sellers typically use ACOS. Agencies and advertisers outside Amazon often prefer ROAS. The best approach is to be comfortable with both since different tools and reports may use either metric.
TACoS (Total Advertising Cost of Sale) is a broader metric that measures total ad spend against total revenue — including organic sales, not just attributed ad sales.
| Metric | Formula | What it tells you |
|---|---|---|
| ACOS | Ad Spend ÷ Ad Revenue | How efficiently your specific ad campaigns perform |
| TACoS | Total Ad Spend ÷ Total Revenue | How advertising affects your entire business profitability |
Why TACoS matters: Strong advertising campaigns often lift organic rankings over time. Your ACOS might stay at 25%, but as organic sales grow, your TACoS drops — meaning your ads are working harder for your total business. A rising TACoS over time signals that your ad spend is growing faster than your organic base, which is unsustainable.
Here is a quick reference for the most common ACOS values and their corresponding ROAS:
| ACOS | ROAS | Interpretation |
|---|---|---|
| 10% | 10:1 | Excellent efficiency |
| 15% | 6.7:1 | Strong performance |
| 20% | 5:1 | Good — target for most categories |
| 25% | 4:1 | Average — needs monitoring |
| 30% | 3.3:1 | Acceptable for low-margin products |
| 33% | 3:1 | Break-even zone for many sellers |
| 40% | 2.5:1 | Likely unprofitable for most categories |
| 50% | 2:1 | Warning — only viable with very high margins |
A high ACOS means you are spending a large share of your revenue on advertising. There is no universal "high" threshold — it depends on your profit margin. But generally:
Common causes of high ACOS:
One of the fastest ways to lower ACOS is to improve your conversion rate. Adding product video to your listing can lift conversions by 15-25%. VEONIB generates professional product videos from any URL in under 60 seconds — no editing required.
It may sound counterintuitive, but a very low ACOS is not always a good thing. Here is why:
The goal is not to minimize ACOS to zero. The goal is to balance ACOS with your profit margins and growth objectives. For established products, 15-25% ACOS is the sweet spot for most categories.
ACOS benchmarks vary significantly by product category. Here are rough guidelines:
| Category | Typical ACOS Range | Profit Margin |
|---|---|---|
| Electronics | 10-20% | Low (10-25%) |
| Clothing & Apparel | 20-35% | Medium (30-50%) |
| Home & Kitchen | 15-25% | Medium (25-40%) |
| Beauty & Personal Care | 25-40% | High (40-60%) |
| Toys & Games | 15-30% | Medium (25-45%) |
| Pet Supplies | 20-30% | Medium (25-40%) |
| Tools & Home Improvement | 12-20% | Low (15-30%) |
| Grocery | 15-25% | Very Low (5-15%) |
For more detailed benchmarks, read our Amazon advertising benchmarks guide.
Here are actionable strategies to lower your ACOS:
For a complete walkthrough of ACOS reduction strategies, see How to Reduce ACOS on Amazon Ads.
Product video is one of the fastest ways to improve your conversion rate and lower your ACOS. VEONIB turns any product URL into a cinematic ecommerce video in under 60 seconds — no editing skills needed. Choose from 6 styles and export ready for Amazon.
Generate your product videoACOS (Advertising Cost of Sale) measures ad spend divided by attributed revenue. The formula is: (Total Ad Spend ÷ Total Ad Revenue) × 100. A 20% ACOS means you spend $0.20 for every $1.00 in sales.
ACOS = (Spend ÷ Revenue) × 100 (a percentage). ROAS = Revenue ÷ Spend (a ratio). They are inversely related. A 20% ACOS equals a 5:1 ROAS.
Generally, lower is better — it means more efficient advertising. But very low ACOS may mean you are under-investing. The right ACOS depends on your profit margins and whether you are in launch mode or maintenance mode.
ACOS measures ad spend vs ad-attributed revenue only. TACoS measures total ad spend vs total revenue (including organic). TACoS gives a more complete picture of how ads affect your overall business.
25% ACOS equals a 4:1 ROAS. The formula is ROAS = 1 ÷ ACOS (as decimal), so 1 ÷ 0.25 = 4.0.
Product video improves conversion rates by 15-25%, which directly lowers your ACOS since the same ad spend generates more sales. VEONIB generates professional product videos from any product URL in under 60 seconds.