MER Calculator
MER (marketing efficiency ratio) is total revenue divided by total marketing spend across all channels — sometimes called blended ROAS.
What is MER?
Platform ROAS can over-count because each platform claims credit. MER uses your real total revenue and total spend, so it shows whether marketing as a whole is working.
How to use the MER calculator (formula)
What each field means
- Total revenue (all channels) — Total store revenue (all channels).
- Total marketing spend — Total marketing spend (all channels).
Worked example
Using these numbers: total revenue (all channels) $90,000, total marketing spend $20,000.
The marketing efficiency ratio is 4.50x.
- Marketing as % of revenue: 22.2%
What is a good MER?
Many ecommerce brands aim for an MER of 3–5. The right target depends on gross margin and fixed costs.
Tips to improve your result
- Track MER weekly alongside platform ROAS.
- Use MER for budget decisions, ROAS for campaign decisions.
- A stable MER while scaling means healthy growth.
- Include agency and creative costs for a strict MER.
Frequently asked questions
What is the MER formula?
MER = total revenue ÷ total marketing spend.
MER vs ROAS?
ROAS is per platform or campaign; MER is the whole business.
Why use MER?
Tracking changes made platform attribution less reliable; MER uses real totals.
How do I improve MER?
Improve retention, conversion rate and creative, and cut channels that do not add revenue.
You might also need
ROAS CalculatorReturn on ad spend from revenue and spend.
E-commerce Profit CalculatorNet profit and margin per order after product, shipping, fees and ads.
Want help improving these numbers?
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