When working with the Meta Ads Reach, you may notice differences in Reach compared to what you see directly in Meta Business Manager.
In Meta Business Manager, the Reach displayed is deduplicated.
→ If the same user is reached multiple times, they are only counted once.
In an API query (and therefore in your Looker Studio and Power BI report or in a query in Google Sheets or Microsoft Excel), Reach is reported per entity (campaign, ad set, ad, or date).
→ It is not deduplicated across entities or dates.
Across different campaigns
One person sees an ad from Campaign A → counted as 1 reach.
The same person sees an ad from Campaign B → counted as 1 reach.
In reports: Total Reach = 2.
In Business Manager: Deduplicated Reach = 1.
Across different dates
One person sees the same ad on Day 1 → counted as 1 reach for that day.
The same person sees the same ad again on Day 2 → counted as 1 reach for that day.
In reports segmented by date: Reach = 2.
For that ad overall: Deduplicated Reach = 1.
The only way to get the same deduplicated Reach as in Business Manager is to:
Create a query that requests Reach directly at the level you want to measure it (campaign, ad set, or account).
This ensures Meta’s API returns the deduplicated Reach value at that level.
Otherwise, when you add breakdowns (by campaign, ad, or date), Reach values will appear inflated compared to Business Manager.
