Media Puppies
Blended ROAS and MER calculator
Every platform grades its own homework, and the sum of their claimed revenue is always larger than what actually landed. This shows the gap in one number.
Set from your location. The maths is the same in any currency — only the labels change.
From your store or accounts, not from any ad platform.
TikTok, affiliates, anything else paid.
Runs entirely in your browser. Nothing you type is sent to us or stored anywhere.
What MER actually is
Marketing efficiency ratio is total revenue divided by total advertising spend. It cannot be inflated by double counting, it does not care about attribution windows, and it reconciles with your accounts. If you track one acquisition number at business level, track this one.
Why platform ROAS is always higher
- The same sale counted twice. A customer sees a Meta ad, then searches your brand and clicks a Google ad. Both platforms claim the sale.
- View-through conversions. Someone scrolled past your ad and bought a week later from an email. The platform takes credit.
- Demand you already had. Branded search and remarketing capture people who were going to buy anyway. Performance Max is particularly good at absorbing this and reporting it as new.
Platform ROAS is useful for deciding between two ad sets. It is not useful for deciding whether to spend more money.
Use both, for different jobs
Inside a channel, platform numbers are the best signal you have for which creative and which audience to back. At business level, MER decides the budget. Problems start when the first number is used for the second job.
The test that settles it
Raise spend by a meaningful amount for a fortnight and watch total revenue, not claimed revenue. If MER holds while spend rises, the channel is genuinely incremental. If claimed revenue rises and total revenue does not move, you have bought attribution, not customers.
Pair this with the contribution margin calculator — MER tells you about revenue, and revenue is not profit.
Questions
What is a good MER?+
Entirely dependent on your margin. A brand with 70% gross margin survives at 3x; one with 25% margin does not. Work out your break-even MER from contribution margin first, then judge.
Should I include organic revenue in total revenue?+
Yes. That is the point. MER measures what the whole business earns against what the whole business spends on ads, which is the only view that cannot be gamed.
What if I do not know what Google claims?+
Leave the claimed figures at zero. You will still get blended MER, which is the number that matters most.
How often should I look at this?+
Weekly for the trend, monthly for decisions. Daily MER is noise, especially for businesses with a long consideration window.
Embed this calculator
Free to use on your own site. Copy this into your page — the attribution line is the only condition.
The paragraph below the iframe is the part that matters: an iframe's contents are served from our domain, so a link inside it is not a link from your page. The paragraph is. The small script just resizes the frame to fit your column — drop it if you prefer, the fixed height still works.
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