#### How does it work?

CPM is shorthand for *cost per thousand* and is a common measure of volume in advertising. Used by both marketers when deciding their advertising budget and publishers when evaluating the value of their users, the calculation is the most frequent metric to determine pricing. The calculator works in multiple ways, to calculate either the cost, CPM, or number of impressions. To calculate simply divide the cost by the number of impressions divided by a thousand. Below is the CPM formula and the reversed equations:

`CPM = 1000 * cost / impressions`

`cost = CPM * impressions / 1000`

`impressions = 1000 * cost / CPM`