The reason ROAS (Return on Ad Spend) shows up differently in Ads Manager vs. Events Manager comes down to how the two tools attribute data and report conversions.
What’s the difference?
1. Attribution Windows
Ads Manager reports ROAS based on the attribution settings you’ve selected (e.g., 7-day click, 1-day view).
Events Manager shows raw, total event data from your Pixel or CAPI (Conversions API), without applying attribution windows or ad-level filtering.
Example:
If someone clicks your ad today but buys five days later, that sale shows up in Ads Manager only if your attribution window includes 7-day click. In Events Manager, it’ll show regardless.
2. Attribution Source
Ads Manager assigns conversions only if it can attribute the event to a Meta ad.
Events Manager shows all Pixel/CAPI events, even ones that come from Google, email, or organic traffic.
3. Deduplication Logic
What to Do:
Double-check your attribution settings in Ads Manager.
Use Breakdown > Attribution Setting to compare event-level reporting.
If you’re running CAPI and Pixel together, make sure deduplication is set up properly.
Remember that Events Manager is diagnostic—not a performance report. Use Ads Manager for ad-level ROAS decisions.