The formula, and the two you get by rearranging it
CPM is the cost of a thousand impressions, so you divide spend by impressions and scale up by 1000. The same relationship runs backwards: impressions = cost ÷ CPM × 1000, and cost = impressions ÷ 1000 × CPM. Give the calculator any two and it fills in the third.
Typical CPM by platform
| Platform | Typical CPM | Note |
|---|---|---|
| Google Display | $0.50–$5 | Wide reach, low intent |
| Facebook / Instagram | $1–$10 | Video costs more than static |
| TikTok | $2–$8 | Varies by season |
| YouTube | $4–$15 | Non-skippable costs more |
| $5–$20 | B2B, highest intent |
Rates swing with your industry too: finance and legal ads can hit $20–$50 CPM, while food and games sit near the bottom. Q4 (Black Friday through Christmas) pushes every rate up 50% or more.
CPM is a pricing model, not a performance metric
- You pay for views, not results. CPM charges for reach regardless of clicks or sales, which is why it suits brand awareness rather than direct response.
- CPC ties the two together. If you know your click-through rate, CPC = (CPM / 1000) ÷ CTR. A $5 CPM at a 1% CTR works out to $0.50 per click.
- A high CPM can still be cheap. LinkedIn's $15 CPM beats a $2 CPM elsewhere if the expensive audience converts at ten times the rate.
Common questions
What does CPM stand for?
Cost per mille, where mille is Latin for thousand. It is the price you pay for one thousand ad impressions, not per click or per sale.
How do I calculate CPM?
Divide total spend by impressions, then multiply by 1000. A $500 campaign that served 100,000 impressions has a CPM of ($500 / 100,000) x 1000 = $5.
What is a good CPM?
It depends on the platform and audience. Google Display runs around $0.50 to $5, Facebook and Instagram $1 to $10, YouTube $4 to $15, and LinkedIn $5 to $20. A high CPM is fine if the audience converts well.
How do I work out impressions from a budget and a target CPM?
Divide the budget by the CPM, then multiply by 1000. With $750 and a $3 CPM you can buy (750 / 3) x 1000 = 250,000 impressions.
