What is CPM?
CPM stands for cost per mille, and mille is Latin for thousand. It is what you pay for 1,000 impressions of your ad, where an impression is one time your ad is shown on someone's screen. Meta Ads Manager, TikTok Ads Manager and Google Ads all report it.
CPM measures the price of attention, not whether your ad works. Two ads with the same CPM can produce very different results, because what happens after the impression (the click, the purchase) is decided by the creative, the offer and the landing page.
The CPM formula
CPM is your ad spend divided by your impressions, multiplied by 1,000. The same formula rearranges to plan a budget or estimate reach, which is what the "Find ad spend" and "Find impressions" buttons above do.
Worked example
You spent $500 and your ad was shown 50,000 times. Divide $500 by 50,000 to get $0.01 per impression, then multiply by 1,000: your CPM is $10.
Planning works the other way. With a $2,000 budget and a CPM of $12, you can expect about 2,000 ÷ 12 × 1,000 = 166,667 impressions.
What drives your CPM on Meta
Meta sells impressions in an auction, so your CPM is set by how many advertisers want the same people at the same time, and by how Meta rates your ad. The main factors:
- Audience and competition: small audiences that many advertisers target cost more per impression than broad ones.
- Time of year: CPMs usually rise in the weeks before Black Friday and Christmas, when more advertisers bid for the same people.
- Placement: Feed, Stories, Reels and Audience Network are priced differently. Advantage+ placements let Meta look for cheaper inventory.
- Country: the same ad costs very different amounts to show in different countries.
- Ad quality and expected engagement: Meta's auction rewards ads people are likely to engage with, so a stronger creative can win impressions for less.
- Optimization goal: campaigns optimized for purchases are shown to people Meta expects to buy, which often costs more per impression than a reach campaign.
Is a high CPM bad?
Not on its own. A high CPM that reaches people who click and buy can produce cheaper sales than a low CPM that reaches the wrong people. Always read CPM next to your click-through rate, cost per click and cost per acquisition.
The three are linked by one formula. At the same CPM, doubling your CTR halves your CPC:
Example: a $10 CPM with a 1% CTR gives a $1.00 CPC. The same $10 CPM with a 2% CTR gives $0.50.
What is a good CPM?
There is no single good CPM. It depends on your country, audience, placement, season and campaign goal, so a number from another account tells you little about yours. The useful benchmark is your own history: track CPM per campaign over time and compare like with like.
A sudden rise on the same audience usually has one of two causes: seasonal competition, or an ad that people have seen too often. When frequency climbs and engagement drops, Meta tends to charge more to keep showing it.
How to lower your CPM
- Broaden your audience so the auction has more people to choose from.
- Refresh creatives before they fatigue. New ads often start with better engagement.
- Test Advantage+ placements instead of Feed only.
- Plan big launches outside the most expensive weeks when you can.
- Work on the hook. An ad that stops the scroll earns engagement, and engagement helps you in the auction.
To see CPM, CPC, CTR, CPA and ROAS together from one set of numbers, use the Meta Ads Metrics Calculator.