Estimate Cost Per Mille (CPM)
CPM expresses advertising cost for every 1,000 impressions.
Formula: CPM = Total Ad Spend Γ· Impressions Γ 1,000
A calculator can make the arithmetic faster, but the assumptions still matter. Check whether the result is a percentage, currency amount, ratio, or rate before comparing it with another figure.
Use the displayed formula as a quick audit trail when checking a result or explaining it to someone else.