Calculate cost per thousand impressions from your campaign cost and reach — or work backward to find the impressions a budget will buy.
CPM stands for cost per mille — the cost of one thousand ad impressions ("mille" is Latin for thousand). It is the standard pricing unit for display, video, and programmatic advertising, where the goal is reach and visibility rather than immediate clicks.
The formula is CPM = (Campaign Cost ÷ Impressions) × 1,000. If a campaign costs $500 and delivers 200,000 impressions, the CPM is ($500 / 200,000) × 1,000 = $2.50. In other words, you pay $2.50 for every thousand times your ad is shown.
You can also rearrange the formula to plan a campaign. Given a CPM and a budget, Impressions = (Budget ÷ CPM) × 1,000. This calculator does both: it computes your actual CPM from cost and impressions, and estimates how many impressions a planned budget will buy at that same rate.
Tip: CPM measures exposure, not response. Pair it with click-through rate and conversion rate to understand whether cheap impressions are actually driving results. A low CPM is worthless if nobody engages.
CPMs vary by platform, audience, and format. Social and display CPMs often run from a couple of dollars to the low teens, while premium video, connected TV, and tightly targeted audiences can cost much more. Narrow targeting raises CPM but usually improves relevance, so judge CPM alongside the quality of the audience you reach.