Marketing Efficiency Ratio (MER) & Contribution Margin Calculator
Platform-reported ROAS hides audience fatigue and returning-customer attribution illusions. Calculate your true blended Marketing Efficiency Ratio (MER), net contribution profit ($ and %), and first-order break-even threshold.
📊 E-Commerce MER & Contribution Margin Calculator
Calculate your true blended Marketing Efficiency Ratio (MER) and post-ad contribution profit to ensure paid media generates cash, not just dashboard ROAS.
MER vs. ROAS: Why MER Governs E-Commerce Cash Flow
Advertising dashboards (like Meta Ads Manager or Google Ads) report return on ad spend (ROAS) based on browser cookies and click models. These platforms routinely take credit for sales that would have happened organically or through brand search. In contrast, Marketing Efficiency Ratio (MER) measures blended store revenue divided by total paid ad spend across all channels:
Marketing Efficiency Ratio (MER) = Total Gross Store Revenue / Total Ad Spend
Break-Even MER = 100 / (100 - COGS% - Shipping% - PaymentFees%)
Industry MER & Margin Benchmarks
| Gross Margin Tier | Break-Even MER | Target Sustainable MER | Target Aggressive Scale MER |
|---|---|---|---|
| High Margin (75%–85%) Apparel, Digital, Niche DTC |
1.18x – 1.33x | 2.50x – 3.20x | 3.80x+ |
| Mid-High Margin (60%–74%) Beauty, Skincare, Supplements |
1.35x – 1.66x | 3.00x – 3.80x | 4.20x+ |
| Standard Retail (50%–59%) Footwear, Home Goods, Hardlines |
1.70x – 2.00x | 3.50x – 4.50x | 5.00x+ |
| Thin Margin (< 50%) Electronics, Consumables, Resellers |
2.10x – 2.50x+ | 4.50x – 6.00x | 6.50x+ |
Read our in-depth tactical guide: Marketing Efficiency Ratio (MER) Benchmarks: What Healthy E-Commerce Brands Maintain and Calculating True New Customer CAC.
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