CPM Calculator
You're paying $4.44 per 1,000 impressions across 450,000 served.
What is CPM?
CPM (cost per mille) is the cost to show your ad one thousand times, calculated as cost divided by impressions, multiplied by 1,000. Spend 2,000 for 450,000 impressions and your CPM is 4.44.
Mille is Latin for thousand, which is why the unit is per 1,000 rather than per single impression: served counts run into the millions, so a price per impression would be unreadably small.
Because every platform quotes it the same way, CPM is the standard yardstick for the price of reach. It tells you what exposure costs, not whether anyone clicked or bought.
How to calculate CPM
CPM = Cost ÷ Impressions × 1,000
- Total the media cost. Add up what you paid the platform for the placement over the period.
- Total the impressions. Count how many times the ad was served, not the unique people reached.
- Divide, then scale to 1,000. Divide cost by impressions, then multiply by 1,000. (2,000 ÷ 450,000) × 1,000 = 4.44.
- Compare across channels. Line up the CPM against your other platforms and past campaigns to see where reach is cheapest.
Worked example
A placement costs 2,000 and serves 450,000 impressions.
| Media cost | $2,000 |
|---|---|
| Impressions | 450,000 |
| Result | $4.44 CPM |
You paid 4.44 for every 1,000 times the ad showed. On its own that is just the price of reach: pair it with CTR and conversion rate to see whether the exposure turned into anything.
How to improve CPM
- Tighten or broaden targeting deliberately: niche, in-demand audiences usually cost more per 1,000 than broad ones.
- Test placements and formats, since feed, stories and in-stream slots carry very different CPMs.
- Mind seasonality: CPMs climb when more advertisers compete, such as the run-up to major shopping dates.
- Remember a low CPM is only good if the reach converts. Cheap impressions to the wrong people are still wasted.
Frequently asked questions
- What is CPM?
- CPM stands for cost per mille: the cost to show your ad one thousand times. It is the standard way to compare the price of reach across ad platforms, which all quote a price per 1,000 impressions.
- How do you calculate CPM?
- Divide your media cost by impressions, then multiply by 1,000. For example, 2,000 in spend for 450,000 impressions is (2,000 ÷ 450,000) × 1,000 = 4.44 CPM.
- What is a good CPM?
- There is no universal figure: CPM varies widely by platform, audience, format and season. Treat it as a comparison tool, benchmarking against your own past campaigns and the channels you are weighing up, not a fixed target.
- What is the difference between CPM and CPC?
- CPM is the cost per 1,000 impressions, so you pay for reach. CPC is the cost per click, so you pay for a visit. CPM suits awareness campaigns priced on exposure, while CPC ties spend to people who actually engage.