CPM calculator
Enter your ad spend and impressions to get your CPM. Add a budget to see how many impressions it buys at that rate.
Formula
CPM = ad spend ÷ impressions × 1,000
CPM stands for cost per mille, mille being Latin for thousand. Impressions count every time the ad was shown, including repeat views by the same person.
New to the term? Read what CPM means in the glossary.
How to calculate CPM: a worked example
A store spends $500 on a Meta campaign and gets 40,000 impressions.
- CPM = $500 ÷ 40,000 × 1,000 = $12.50
- Each impression cost $0.0125
- At that rate, a $2,000 budget buys 160,000 impressions
The store paid $12.50 every time its ad was shown 1,000 times.
What is a good CPM?
A low CPM is only good if the impressions turn into orders. The highest CPM you can afford comes from your break-even CPA, click-through rate and conversion rate: max CPM = break-even CPA × CTR × conversion rate × 1,000.
With a $34 break-even CPA, a 1.2% CTR and a 2.5% conversion rate, the most this store can pay is $10.20. At $12.50 it loses money unless more people click or more clicks buy. The table shows the ceiling for other rates.
| CTR | 1.5% conversion rate | 2.5% conversion rate | 4% conversion rate |
|---|---|---|---|
| 0.8% | $4.08 | $6.80 | $10.88 |
| 1.2% | $6.12 | $10.20 | $16.32 |
| 2.0% | $10.20 | $17.00 | $27.20 |
Questions about CPM
- What does CPM stand for?
- CPM stands for cost per mille, the price of 1,000 ad impressions. Ad platforms such as Meta, TikTok and Google show it for every campaign, and it's how most display and social ads are priced when you optimize for reach.
- Why did my CPM go up?
- CPM rises when more advertisers compete for the same audience, as they do before holidays, or when your audience is narrow. Weak ads can also raise it, because platforms charge more to show ads people ignore.
- Is CPM or CPC better to track?
- Track both. CPM tells you what reach costs; CPC tells you what attention costs. A cheap CPM with a poor click-through rate can cost more per click than an expensive CPM with ads people click.
Do it with Replo
See CPM next to what it sold
Replo puts CPM, CTR and orders side by side, so you know which costly reach still pays.
Prompt: “show CPM, CTR and orders by campaign this month”