MER calculator
Calculate blended marketing efficiency from total net revenue and all marketing spend.
Last updated
Your results
- MER
- 3×
- Total business revenue for each £1 of total marketing spend. Not incremental sales or profit.
How to use this tool
Use one reporting window and a consistent measurement scope. Replace the example inputs with your own figures. The result updates locally as you type. Copy the result to your planning notes, or copy a link containing only the numeric inputs. Reset restores the illustrative example.
- Enter total revenue for the period from all channels.
- Enter total marketing spend for the same period.
- Read the marketing efficiency ratio.
- Compare against your break-even and track it over time.
Worked example
£12,000 net store revenue divided by £4,000 total marketing spend gives MER 3.0. Every £1 of marketing spend corresponds to £3 revenue in this reporting window, not £3 profit or incremental revenue.
Formula and units
MER = total net business revenue / total marketing spend.
Assumptions and review notes
MER avoids adding overlapping platform-attributed sales, but includes organic, email and repeat-customer revenue. Strong MER does not prove a paid campaign caused the sales. Keep the cost scope fixed between weeks and compare similar trading periods. A launch or promotion may produce delayed revenue and front-loaded costs.
MER avoids attribution disputes but cannot say which channel works. It suits whole business monitoring, and it needs comparing against margin like ROAS.
- Spend included.
- Organic and repeat share.
- Seasonality.
- Margin.
- Excluding agency or creative costs.
- Mixing periods.
- Using it to judge one campaign.
- Ignoring margin.
A closer look
Common questions.
- What is MER?
- Total revenue divided by total marketing spend.
- MER or ROAS?
- MER is blended, ROAS is channel attributed.
- What spend counts?
- All marketing spend you want judged.
- Is higher always better?
- Usually, but growth may need lower efficiency.
- Does it store data?
- No.