ACOS (Advertising Cost of Sale) tells you what percentage of your ad-generated revenue you’re spending on advertising. It’s the single most important PPC metric for knowing whether a campaign is actually making you money.
The Formula
| Metric | Formula |
|---|---|
| ACOS | (Ad Spend ÷ Ad Sales) × 100 |
| ROAS | Ad Sales ÷ Ad Spend |
| Break-even ACOS | Equal to your product’s profit margin % |
Worked Example
Say you spent $150 on ads and those ads generated $750 in sales, on a product with a 30% profit margin:
| Input | Value |
|---|---|
| Ad Spend | $150 |
| Ad Sales | $750 |
| ACOS | 20% |
| ROAS | 5.0x |
| Break-even ACOS (30% margin) | 30% |
| Verdict | Profitable — ACOS (20%) is below break-even (30%) |
Quick Reference: ACOS by Ad Spend and Sales
| Ad Spend | Ad Sales | ACOS | ROAS |
|---|---|---|---|
| $50 | $500 | 10% | 10.0x |
| $100 | $500 | 20% | 5.0x |
| $150 | $500 | 30% | 3.3x |
| $200 | $500 | 40% | 2.5x |
| $250 | $500 | 50% | 2.0x |
How to Use This
- Pull your Ad Spend and Ad Sales from Amazon Advertising > Campaign Manager for the date range you want to check.
- Divide Ad Spend by Ad Sales, multiply by 100 — that’s your ACOS.
- Compare it against your break-even ACOS (your profit margin %). Below it = profitable campaign; above it = losing money on that ad spend.
- Track ACOS by campaign, not just account-wide — a healthy average can hide underwater campaigns.
Want us to run this on your actual account? We’ll audit your campaigns and tell you exactly which ones are profitable.
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