CPM Calculator
Cost per thousand impressions, solved in any direction: enter any two of cost, impressions and CPM, get the third with the formula shown. Then take the same numbers through the full funnel below.
CPM solver enter any two, the third is solved
Full funnel
Unit economics: contribution and break-even bids
Scenario planner arithmetic from your assumptions, not a forecast
Show the math
Impressions are not people
The oldest confusion in media buying: a 100,000-impression buy does not mean 100,000 people saw your ad. Impressions count displays; reach counts unique humans, and the ratio between them is frequency. CPM math can never produce reach by itself, which is why this page labels every derived volume "expected impressions" and offers reach only as an estimate that you drive with a frequency assumption. Platforms report deduplicated reach from data you cannot reconstruct; the honest local math stops at impressions.
CPM, the formula and a worked example
CPM is the cost per thousand impressions: spend divided by impressions, multiplied by 1,000. A placement that cost 480 for 120,000 impressions has a CPM of 4.00. The calculator runs the formula in every direction, so you can also start from a CPM and a budget to see how many impressions it buys, or from a target reach to see what it will cost.
The same formula prices very different things. A display network CPM of 2 buys impressions that are often below the fold or never seen by a person; a newsletter sponsorship at a 40 CPM buys an impression that was opened on purpose. Viewable CPM (vCPM) counts only impressions that met the viewability standard, and it is always higher than the raw CPM for the same money, because the denominator is smaller.
CPM misleads when impressions and people are treated as the same thing. 120,000 impressions might be 12,000 people seeing an ad ten times, and frequency, not impressions, decides whether the money did anything. It also misleads across formats: a 4 CPM video placement and a 4 CPM banner are not equal buys. Use CPM to compare like with like, then move to CPC, CPA or ROAS for the question that matters, which is what the impressions turned into.
CPM FAQ
How is CPM calculated?
CPM = cost / impressions x 1,000: the cost per thousand times your ad is shown ("mille" is Latin for thousand). $900 for 50,000 impressions is an $18 CPM. The solver above works in all three directions: it also finds the impressions a budget buys at a given CPM, or the cost of a target impression volume, showing the rearranged formula each time.
How many impressions does my budget buy?
Impressions = budget / CPM x 1,000. A $1,000 budget at a $10 CPM buys 100,000 impressions. Note what that number is: impressions, times an ad is displayed, not reach. The same person seeing your ad five times is five impressions and one reached person; estimating reach requires dividing by an average frequency, which the planner section handles as a labeled estimate.
What is a normal CPM?
It varies too much for one number to be honest: channel, format, audience, country, seasonality and objective each move CPM by multiples, and any calculator quoting a universal "typical CPM" is decorating. What is comparable is your own CPM across campaigns and over time, and what matters more is what those impressions convert into, which the full funnel below computes.
CPM vs CPC vs vCPM: which pricing am I in?
CPM bills per thousand displays regardless of interaction; vCPM bills per thousand VIEWABLE impressions (rendered where they could be seen); CPC bills per click regardless of displays. The same campaign can be evaluated in any of them: divide spend by the matching count. This page computes CPM and CPC side by side in the funnel so the comparison is one glance.
More free tools: Ad Metrics Calculator · CTR Calculator · CPA Calculator · ROAS Calculator