CPM Calculator

CPM, or cost per mille, is what you pay for 1,000 impressions of an ad. It is how most display, video and social advertising is priced and compared, and the first number to check when a campaign suddenly costs more: rising CPMs mean the audience got more expensive to reach, before anyone has clicked.

Rearranged, the same relationship solves for the other two values, which is what the calculator's modes do:

Use CPM to plan reach: once you know a typical CPM for your audience, the spend mode tells you what a target number of impressions will cost, and the impressions mode tells you what a fixed budget will buy.

Then connect it to results. CPM only prices attention; what matters is how much of that attention turns into clicks and sales. Your cost per click is CPM divided by (click-through rate × 1,000), which the CPC calculator works out if you add impressions. To see whether the whole campaign pays, check its ROAS.

• Chasing the lowest CPM

  Cheap impressions are often cheap because they reach people unlikely to buy. A higher CPM with better targeting can produce cheaper sales.

• Confusing impressions with reach

  Impressions count every view; reach counts people. A high frequency can make CPM look efficient while the same people see the ad over and over.

• Comparing CPMs across very different placements

  Video, feed, search and display inventory are priced differently. Compare like with like.