Formulas used by this calculator
- MER = total business revenue ÷ total included marketing spend
- Marketing spend share (%) = included marketing spend ÷ total business revenue × 100
Worked example
Illustrative business revenue is $50,000 and included marketing spend is $10,000. MER is 5× and marketing spend is 20% of revenue.
If a media-only view includes $8,000 instead, that ratio becomes 6.25×. The business did not suddenly improve; the cost definition changed.
Set a consistent marketing-spend definition
Shopify describes MER as total revenue divided by total marketing spend and notes that cost definitions differ between businesses. Shopify: marketing efficiency ratio.
Choose whether media, creators, creative production, software, contractors, and marketing labor belong in your review. Use the same rule each period. If your team also needs a media-only ratio, calculate it separately and label it clearly.
Keep blended revenue separate from attribution
The revenue input can include returning customers, direct visits, organic discovery, and other demand within the business scope. Dividing that total by marketing spend does not prove marketing caused every sale. MER is a business-level efficiency view, not a causal allocation of revenue.
Use compatible revenue treatment across reports. A refund-adjusted business total and gross attributed platform revenue answer different questions. Reconcile currencies, refunds, taxes, and timing before explaining why MER and a channel's ROAS differ.
Use the ratio with contribution and growth
A high ratio can coexist with slow new-customer acquisition. A lower ratio can accompany a deliberate investment whose benefits arrive later. Neither interpretation follows from the ratio alone; examine acquisition, contribution, retention, and the purpose of the spend.
The inverse percentage makes the cost share easy to discuss, but it is not a profit margin. Product costs and operating expenses remain outside this calculation unless they are part of a separate economics review. Save the worksheet with the cost-scope notes that make comparisons possible.
Common questions
Is MER the same as blended ROAS?
Teams sometimes use those terms for similar ratios, but the denominator may differ. This calculator explicitly uses total included marketing spend. Reconcile the definitions before treating two named metrics as equivalent.
Does a 5× MER mean a 400% profit?
No. It means five units of business revenue per unit of included marketing spend. Serving costs, overhead, timing, and other expenses are not covered by that arithmetic.