CPM (Cost per Mille (Cost per 1,000 Impressions))
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CPM is the cost an advertiser pays for 1,000 ad impressions, used to compare media costs across platforms and campaigns.
CPM — from the Latin "mille" meaning thousand — is the standard unit for pricing ad inventory. It strips out audience size, creative quality and conversion rates, making it the cleanest apples-to-apples cost benchmark.
Most digital ad auctions run on a CPM basis under the hood, even if you optimise for clicks or conversions. The platform bids on impressions and the algorithm decides which impressions are most likely to produce your desired outcome.
Typical 2025–26 ranges: Meta $5–$15, TikTok $4–$10, YouTube $6–$15, Google Display $1–$4, LinkedIn $25–$60. Higher CPMs often correlate with higher-intent audiences, so a higher CPM isn't automatically bad.
Formula
CPM = (Total ad spend ÷ Impressions) × 1,000
Example
Related terms
CPC
CPC is the average cost you pay each time someone clicks your ad, calculated as total ad spend divided by total clicks.
CTR
CTR is the percentage of people who click your ad after seeing it, calculated as clicks divided by impressions times 100.
Ad Frequency
Ad frequency is the average number of times a single user sees your ad within a given time period.
ROAS
ROAS is the revenue earned for every dollar spent on advertising, expressed as a multiple (4x means $4 back per $1 spent).