MER and blended ROAS are the same number: total revenue over total marketing spend, every channel included. This works out what you’re getting, and what the business can actually afford.
Total revenue and total spend across every channel, not just Meta.
Used to work out the MER you actually need, not just the one you're getting.
Running 2.20 above the MER you need: that's the cushion funding everything else.
The spreadsheet version, plus how MER and per-channel ROAS relate when they disagree.
For the per-order version: the ROAS you actually need to see
One calculator rarely tells the whole story. This is the order that actually works: from margin, to target, to a page that can convert the traffic you send it.