What do Meta ad metrics measure?

Ads Manager reports dozens of columns, and the ones advertisers read most fall into three groups. Delivery metrics count how often Meta showed an ad, to how many accounts, and what that exposure cost. Engagement metrics count what people did on the ad itself. Outcome metrics count the business actions, such as purchases or leads, that Meta credits to the ad.

The groups answer different questions, and they can move in opposite directions. Meta notes that results may not match how you are billed. An ad set can count purchases as its results while Meta charges it for impressions. A low CPM and a low cost per purchase are different achievements, and an online shop is paying for the second.

Meta counts an impression each time an instance of an ad appears on screen for the first time. If someone scrolls past an ad and back to it, that is one impression. If the ad appears on their screen at two different times in a day, that is two. A video does not have to start playing for the impression to count, and Meta excludes invalid traffic it detects, such as bots.

Reach is the number of Meta accounts that saw the ad at least once. Meta labels reach an estimate calculated from sampled data. Because reach counts unique accounts, it does not add up across ad sets. Meta's own example has one ad set reaching persons A and B and another reaching B and C. Each ad set has a reach of 2, and the campaign has a reach of 3.

Frequency is impressions divided by reach, the average number of times each account saw the ad. CPM, cost per 1,000 impressions, is amount spent divided by impressions, multiplied by 1,000. It is the price of the exposure an ad set won in the Meta ad auction, and it says nothing on its own about what that exposure produced.

Meta separates link clicks from all other clicks. A link click is a click, swipe or other gesture on a link in the ad that leads to a destination the advertiser chose, on or off Meta technologies. Clicks (all) includes link clicks plus post likes, comments and shares, clicks to the Facebook Page or Instagram profile, and clicks that expand a photo or video to full screen.

That split produces two click-through rates. CTR (all) is clicks (all) divided by impressions. CTR (link click-through rate) is link clicks divided by impressions. Both share the same denominator and clicks (all) contains every link click, so CTR (all) is always at least as high as link CTR. The gap widens on ads that draw comments, shares or profile visits.

CPC (cost per link click) is amount spent divided by link clicks. Link clicks matter beyond the click columns. Meta uses them for click-through attribution, and since March 2026 they are the only clicks that count towards it for website and in-store conversions.

Results is the number of times an ad achieved the outcome set by its objective and settings, such as a purchase, a lead or a landing page view. Meta counts results under the ad set's attribution setting. Its default is 7-day click, 1-day view and 1-day engagement, so a purchase can count as a result when the buyer saw the ad and never clicked it. Where data is partial or missing, Meta may use statistical modelling for some results.

Cost per result is amount spent divided by results. Meta says it depends on the bid, the audience, the optimisation type, the creative and messaging, and the schedule. It is the number most advertisers call CPA, cost per acquisition.

Purchase ROAS, return on ad spend, is purchase conversion value divided by amount spent. Meta builds it from purchase data sent by your connected Meta Business Tools, such as the Meta Pixel, and attributed to your ads. Meta notes that it may be estimated, may use statistical modelling, and may not be calculated for some results from devices on iOS 14 and later. A ROAS calculator runs the same sum on figures from your own store.

Each row uses the formula from Meta's Business Help Centre.

Each metric is accurate as Meta defines it. Problems start when one is read as a verdict on the ad.

• CPM. Meta warns that when an ad set optimises for conversions, CPM may not be a good indicator of performance, because the system may buy more expensive impressions if that is how it gets cheaper conversions. A rising CPM alongside a falling cost per result means the system made that trade.

• CTR (all). It counts likes, comments and profile clicks, so an ad can post a high CTR (all) while sending few people to the site. Use link CTR when the goal is traffic or sales.

• CPC. A low cost per link click says nothing about what visitors did next. Cheap clicks from people who do not buy still raise cost per result.

• Reach and frequency. Both are estimates from sampled data, and reach does not add up across ad sets, so summing reach across rows overstates the audience.

• Results and purchase ROAS. Both depend on the attribution setting. The same sales give a lower result count and ROAS under 1-day click than under the default, which also credits views and engagements. How Meta attribution works explains the windows.

Meta's advice is to focus on the cost of the optimisation event you chose for the ad set, and to judge performance over at least a full week, because hourly and daily figures swing and average out. Delivery and engagement metrics then explain why that cost moved.