Glossary
Reach: what it is and how it differs from impressions
What reach means in Meta Ads, how it differs from impressions, why reach never adds up across campaigns, and what actually moves the number.
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Reach is the number of unique people who saw your ad at least once inside the period and scope you selected. If 8,000 people saw an ad 24,000 times, reach is 8,000 and impressions are 24,000. Reach answers "how many people", impressions answer "how many deliveries". The distinction matters because reach is deduplicated, and deduplicated numbers do not add up the way media buyers expect them to.
Formula
Reach is counted, not calculated. Meta deduplicates people inside the scope you asked for. What you can derive is the relationship to the other two numbers:
Reach = impressions ÷ frequency.
That is the same identity as frequency equals impressions divided by reach. It only holds inside one scope and one date range. Outside that, it breaks:
| What you have | Can you add it up? |
|---|---|
| Impressions, day by day | Yes |
| Spend, day by day | Yes |
| Reach, day by day | No, the same person shows up on several days |
| Reach of campaign A and campaign B | No, both can hit the same person |
So a month of reach is smaller than the sum of the four weeks, and account reach is smaller than the sum of the campaigns. If a report shows "total reach: 1.2 million" built by adding rows, that number is fiction.
One practical note: Meta removed Page-level reach from the API. Any tool that reads the API can report ad reach, not organic Page reach. Judge Page performance on engagement, visits and follower growth instead.
What a good number looks like
Reach has no target of its own. It is a denominator. Read it against three things:
- Against your addressable audience. Reaching 40,000 of a 60,000-person audience is a different situation from reaching 40,000 of 4 million.
- Against frequency. Reach flat while impressions climb means you are paying to repeat yourself.
- Against results. Reach rising with results flat means the new people are the wrong people.
A campaign whose reach stops growing while spend keeps rising has run out of new people to talk to. That is the signal, not the raw count.
What makes the number move
- Budget, up to a point. Once the eligible pool is saturated, extra spend buys repetition, not people.
- Audience size and exclusions. Tight targeting caps reach by design.
- Objective and optimization. Optimizing for a conversion event concentrates delivery on fewer people than optimizing for reach does.
- Placement mix. Opening more surfaces usually widens the pool.
- Overlap between your own ad sets, which quietly costs you both reach and money.
Read reach with two other columns
Never read reach alone. Put it next to impressions and CPM for the same dates and you can tell audience growth apart from repetition. The paid media reporting page shows how to keep all three in one view instead of three exports. What each of the two counts actually measures, and why reach does not add across months, is in reach or impressions.
Frequently asked questions
What is the difference between reach and impressions?
Reach counts unique people who saw the ad at least once. Impressions count every delivery, including repeat views to the same person.
Can I add the reach of two campaigns together?
No. The same person can be reached by both, so the sum overstates your audience. Read reach at the level you actually care about.
Can I still report Facebook Page reach?
Meta removed Page-level reach from the API, so tools that read the API cannot report it. Ad reach from the ads API is unaffected.