What ACoS can you actually afford?
Enter your price + costs. Get your break-even ACoS and a sane target range in 30 seconds.
Break-even ACoS is the tipping point between profit and loss on every ad-attributed sale. Knowing your exact number prevents wasted ad spend and helps you set realistic bid targets. Scroll down for detailed explanations of ACoS, ROAS, and TACoS →
Product Economics
Storage fees, prep costs, etc.
Enter Your Numbers
Fill in your selling price and costs above to calculate your break-even ACoS
Understanding Your Amazon PPC Metrics
ACoS
Advertising Cost of Sale
Measures ad spend as a percentage of ad-attributed sales only. Lower is better, but only tells part of the story.
ACoS = (Ad Spend / Ad Revenue) × 100ROAS
Return on Ad Spend
The inverse of ACoS, revenue generated per dollar spent. Higher is better. A 4x ROAS = 25% ACoS.
ROAS = Ad Revenue / Ad SpendTACoS
Total Advertising Cost of Sale
Ad spend as a percentage of total revenue (including organic). Shows true ad dependency.
TACoS = (Ad Spend / Total Revenue) × 100Many sellers obsess over ACoS alone, but this can be misleading. A campaign with 50% ACoS might look terrible, until you realize it's driving organic sales that don't show up in ad attribution. That's why experienced sellers track TACoS as their north star metric: it reveals whether advertising is building sustainable organic momentum or just buying sales.
Break-Even Math Explained
Your break-even ACoS is simply your profit margin expressed as a percentage of your selling price. Here's the logic:
Example Calculation
At 40% ACoS, you spend $12 per sale on ads, exactly your profit margin. Below 40%, you're profitable. Above 40%, you're losing money.
High-margin products (40%+ profit margin) give you room to bid aggressively and still profit. These products can run 30-35% ACoS while remaining solidly profitable. Low-margin products (15-20% profit margin) require surgical precision, there's little room for error, and even slightly inefficient campaigns can erase your profits.
Common ACoS Pitfalls to Avoid
Ignoring Amazon's 15% referral fee
Many sellers calculate break-even using just COGS + FBA. The referral fee is often the largest single cost and dramatically affects your real margin.
Chasing arbitrary ACoS targets
"20% ACoS is good" isn't universally true. A product with 50% margins can thrive at 35% ACoS; a product with 20% margins dies at 25% ACoS. Calculate YOUR numbers.
Forgetting variable costs
Storage fees, returns, packaging, prep fees, these add up. Include them in "Other Costs" for an accurate break-even calculation.
Comparing ACoS across different products
A 30% ACoS on a high-margin product is more profitable than 20% ACoS on a low-margin product. Compare performance to each product's break-even, not to each other.
Optimizing ACoS while ignoring TACoS
Cutting "inefficient" campaigns can tank your organic rankings. Watch TACoS to ensure you're not sacrificing long-term growth for short-term ACoS improvements.
Not recalculating after cost changes
Amazon fees change annually (usually February). Supplier costs fluctuate. Your break-even ACoS from last year may be dangerously wrong today.
The sellers who profit consistently aren't the ones with the lowest ACoS, they're the ones who know exactly what ACoS they can afford and optimize to that specific target. Use this calculator every time you launch a new product, adjust your pricing, or see a cost change. Your break-even ACoS is the foundation of profitable Amazon advertising.
Frequently Asked Questions
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