MER calculator
Marketing Efficiency Ratio. Channel-agnostic, attribution-noise-proof.
Inputs
Results
MER = Total revenue / Total marketing spend
Higher is better. Healthy ecom typically 3-5x. Hyper-scale brands sometimes 2-3x by design.
Marketing % = Total marketing spend / Total revenue × 100
Inverse view of MER. Most healthy ecom sits at 20-30%. Above 35% means efficiency problems.
Why this calculator is verified
MER (also called blended ROAS) is the only marketing metric that survives modern attribution loss. iOS 14, cookie deprecation, and ad-blocker prevalence broke channel-level attribution; MER bypasses the problem by dividing total revenue by total marketing spend. The ratio is what every CFO ultimately reports up. Triple Whale, Northbeam, and the entire post-iOS attribution literature converged on this metric as the channel-agnostic truth.
Worked example
Mid-stage DTC brand, $250K revenue, $60K marketing
MER = $250,000 / $60,000 = 4.17. Marketing % of revenue = 24%. Healthy. The same brand at $80K marketing would have MER 3.13 and marketing % at 32%, which is the edge of healthy. Above 35% marketing-to-revenue, something in the funnel needs to change before more spend is added.
Sources for the formula
- Andrew Faris (4x400), MER as the operator north star
Operator primer. Frames why MER survives where channel ROAS fails.
- Triple Whale, MER methodology
Vendor-published spec. Useful for the formula and the rationale.
- Northbeam, blended ROAS vs channel ROAS
Cross-checks the methodology from a measurement-platform angle.
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