Amazon PPC ACOS (Advertising Cost of Sales) is the most debated metric in Amazon selling. "What ACOS should I target?" is asked in every seller group, and the answer is almost always "it depends." This guide cuts through the confusion with clear formulas, real examples, and a framework for knowing what ACOS you should actually target for your specific business.
How Is Amazon ACOS Calculated?
ACOS measures how much of your ad revenue you're spending on advertising. It's expressed as a percentage — the lower the ACOS, the more efficient your advertising.
Key Metric: ACOS (Advertising Cost of Sales)
Formula: ACOS = (Ad Spend รท Ad-attributed Sales) ร 100
Benchmark: 15โ30% is typical; below 20% is strong for competitive categories
Example: You spend $500 on ads and those ads generate $2,000 in sales. ACOS = $500 รท $2,000 ร 100 = 25%
What Is the Difference Between ACOS and TACOS?
ACOS only measures ad-attributed sales. TACOS (Total Advertising Cost of Sales) measures ad spend against your total revenue — including organic sales that the ad may have indirectly driven.
Key Metric: TACOS (Total Advertising Cost of Sales)
Formula: TACOS = (Ad Spend รท Total Revenue) ร 100
Benchmark: 5โ15% for mature brands with organic synergy
Example: Same $500 ad spend, but total store revenue is $5,000 (including organic). TACOS = $500 รท $5,000 ร 100 = 10%
TACOS is a better metric for mature campaigns because it accounts for the halo effect — ads that help your organic rank also generate non-ad sales. Use ACOS for evaluating individual campaigns and TACOS for evaluating your overall advertising strategy.
How Does RoAS Compare to ACOS?
RoAS (Return on Ad Spend) is simply the inverse of ACOS. Where ACOS tells you what percentage of revenue goes to ads, RoAS tells you how much revenue you generate per dollar spent.
Key Metric: RoAS (Return on Ad Spend)
Formula: RoAS = Ad-attributed Sales รท Ad Spend
Benchmark: 4x+ is healthy; 10x+ is excellent for ecommerce
| ACOS | RoAS | Meaning |
|---|---|---|
| 10% | 10.0x | Very efficient |
| 20% | 5.0x | Good |
| 25% | 4.0x | Healthy |
| 33% | 3.0x | Marginal |
| 50% | 2.0x | Breaking even on ads |
| 75% | 1.33x | High ACOS, brand awareness mode |
What Is Your Break-Even ACOS?
Your break-even ACOS is the point where you neither profit nor lose on your ads. It equals your gross margin percentage. Any ACOS below this is profitable advertising.
Key Metric: Break-Even ACOS
Formula: Break-Even ACOS = Gross Margin ร 100
Tip: Run any ACOS above this and you lose money per sale
Example: You sell a product at $49.99. Product cost ($12) + FBA fee ($5.50) + referral fee ($7.50) = $25 total cost. Gross profit = $24.99. Gross margin = 50%. Break-even ACOS = 50%.
If your ACOS is 30%, you make profit on ads. If your ACOS is 60%, you're paying $0.60 per dollar of sales to advertising — losing money on every sale but building rank and reviews.
What Is a Good ACOS by Amazon Category?
| Category | Typical ACOS Range | Notes |
|---|---|---|
| Electronics & Accessories | 15โ25% | High competition, good margins |
| Beauty & Personal Care | 20โ35% | High demand, high competition |
| Home & Kitchen | 20โ30% | Broad category, varied margins |
| Clothing & Apparel | 25โ40% | Seasonal, lower margins |
| Toys & Games | 20โ35% | Q4 heavy, competitive |
| Sports & Outdoors | 20โ30% | Broad, good margins |
How to Lower Your ACOS
- Improve listing conversion rate: ACOS is partly a function of how well your listing converts. Better images, copy, and A+ content mean more sales per click — reducing ACOS without changing bids.
- Tighten keyword match types: Use phrase and exact match for proven keywords. Broad match burns budget on irrelevant clicks that never convert.
- Add negative keywords daily: Review search term reports and add irrelevant queries as negatives. This prevents wasted spend on non-converting searches.
- Lower bids on well-performing keywords: Once a keyword consistently converts at low ACOS, gradually reduce bids to maximize ROI.
- Use automatic campaigns to find targets, then replicate in manual: Let automatic campaigns discover what's working, then bid higher on those targets in manual campaigns for better control.
- Optimize product relevance: Bid more on keywords directly related to your product. Bid less (or exclude) keywords for adjacent but different products.