Cost Per Mille (CPM)

The cost of 1,000 ad impressions.

By Brandon MinaCEO, BrandPilot AIUpdated November 2026

Short answer

Cost per mille (CPM) is the price an advertiser pays for one thousand ad impressions, with mille meaning thousand in Latin. It is calculated by dividing total cost by impressions and multiplying by 1,000. CPM is the standard pricing unit for display, video, and CTV, making it useful for comparing the cost of reach across channels.

A man in a suit pours a stream of tiny eyes into a measuring jar on a balance scale weighed against a small stack of coins. 1960s ink-and-gouache magazine-ad illustration. — CPM: the price of a thousand impressions.