CPM (Cost per Mille)
MetricCPM is the cost of displaying an ad one thousand times (mille is Latin for thousand).
What is CPM, in plain English?
CPM is the industry standard price for eyeballs. If an ad network charges a $20 CPM, it means you pay $20 for every 1,000 times your ad appears on someone’s screen.
How do you calculate CPM?
CPM = (Ad Spend ÷ Total Impressions) × 1,000
CPM example
An ad campaign spends $500 and is displayed 25,000 times. CPM = ($500 ÷ 25,000) × 1,000 = $20.
Common CPM mistakes
High CPMs are common in competitive, high-intent audiences (like B2B executives or enterprise buyers). A $100 CPM targeting CTOs can be vastly more profitable than a $3 CPM targeting broad entertainment audiences.
What is a good CPM?
CPM varies widely by audience, platform, placement and season, so the useful comparison is your own trend. A rising CPM with a flat conversion rate pushes CPA up; a high CPM is fine if the audience converts well enough to keep CPA under target.
CPM FAQs
How do you calculate CPM?
Divide ad spend by impressions and multiply by 1,000: $300 for 60,000 impressions is a $5 CPM.
Why do CPMs rise during festive and sale seasons?
More advertisers compete for the same users, and auctions price impressions by demand. Expect higher CPMs then and judge campaigns on CPA or ROAS, which can still hold up because purchase intent rises too.
How does CPM relate to CPC and CTR?
CPC = CPM ÷ (CTR × 1,000), with CTR as a decimal. A $10 CPM with a 1% CTR gives a $1.00 CPC; doubling CTR halves the CPC at the same CPM.
Last reviewed October 3, 2026.