All tools
Calculator
True ROAS & MER
Convert platform-reported ROAS into blended MER and attribution-adjusted true ROAS per channel. Live as you type.
Your numbers (last 30 days)
Result
Blended MER
3.85x
Total ad spend
€130,000
Reported vs real gap
6.4%
Channel overlap
0.94x
Meta true ROAS
2.72x
Google true ROAS
4.44x
TikTok true ROAS
2.29x
Blended MER is total revenue ÷ total ad spend — the only number that can't lie. If channel overlap is above 1.3x, your platforms are double-counting the same orders.
Want a CFO to pressure-test your real MER?
A free 30-minute call – we'll rebuild blended attribution on your actual numbers.
30 min · No pitch · A real CFO, not a chatbot