MER Calculator (Marketing Efficiency Ratio)
Total revenue divided by total marketing spend. See your MER and how much platform dashboards over-claim vs. what actually hit the bank.
What MER measures vs ROAS
ROAS is what one ad platform says it returned on its own spend. MER (marketing efficiency ratio) is total business revenue divided by all marketing spend: paid media plus non-ad costs like creative, agency fees, and software.
MER lines up with your P&L. ROAS lines up with Ads Manager. When leadership asks whether marketing is working, MER is usually the number worth bringing to the meeting.
For the full comparison, decision rules, and board-meeting framing, read MER vs ROAS for Meta ads.
How to read the attribution overlap gap
Enter channel spend and each platform's reported ROAS. The calculator sums attributed revenue (what the dashboards claim) and compares it to actual revenue.
- Large positive gap (30%+): channels are double-counting sales. Scaling on platform ROAS alone can mislead you.
- Moderate gap (10 to 30%): normal in multi-channel programs. Anchor budget decisions to MER.
- Negative gap: platforms under-report vs. Shopify or your bank account. Common with dark social and direct traffic.
Pair MER with Facebook ads ROAS benchmarks when you set channel-level targets.
Healthy MER ranges (quick reference)
| MER | Typical read (DTC) |
|---|---|
| Below 2.0x | Often unprofitable after variable costs |
| 2.0 to 3.0x | Watch zone; depends on gross margin |
| 3.0 to 5.0x | Healthy for many ecommerce brands |
| Above 5.0x | Strong efficiency; room to scale if growth is the goal |
Your margin structure always overrides generic bands.
FAQ
What is a good MER for ecommerce?
Many DTC brands target roughly 3.0x to 5.0x MER depending on gross margin and repeat purchase rate. A 3x MER at 70% gross margin feels very different from 3x at 40% margin.
What is the difference between MER and ROAS?
ROAS is channel-specific and platform-reported. MER is total revenue divided by total marketing spend across every channel and cost center. Use ROAS to tune ads; use MER to defend the overall program.
How do you calculate marketing efficiency ratio?
MER = total business revenue / total marketing spend. Include ad spend plus non-ad marketing costs (creative, agency, software, influencers) in the denominator for a true program read.
Why does Meta ROAS not match Shopify revenue?
Attribution overlap, view-through credit, and iOS reporting gaps inflate platform ROAS. MER uses bank-deposit reality instead of dashboard credit.
Defending budget? Show competitors too.
MER explains your program. The free Meta Ad Library sample reports show how long rivals keep ads live, which helps you argue whether the category is spending efficiently or buying growth.