Formula
CPM = amount spent ÷ impressions × 1,000. To plan: impressions = budget ÷ CPM × 1,000. People reached = impressions ÷ frequency.
Example
$500 for 100,000 impressions is a $5.00 CPM. A $2,000 budget at the same CPM buys 400,000 impressions; at a frequency of 2, that is about 200,000 people.
When to use CPM
For awareness and reach campaigns, where the goal is to be seen. For sales, also track the CPA.
Frequently asked questions
What is frequency?
How many times, on average, each person saw the ad. A frequency of 3 means 30,000 impressions reached about 10,000 people.
What makes CPM go up?
Small or highly contested audiences, holiday seasons and ads with low relevance.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.