📢 Advertising
Ad Impressions to CPM Cost
Work out campaign cost from impressions and CPM, or the impressions a budget buys. Add clicks for CTR and CPC, then press Convert.
About the Ad Impressions to CPM Cost
CPM means cost per mille — cost per thousand impressions. If the CPM is $5 and the campaign delivers 200,000 impressions, the media cost is 200 × $5 = $1,000. Impressions are counted when the ad is served, not when someone clicks, so CPM campaigns can be cheap per view and expensive per visit.
This calculator solves the CPM equation in any direction. It also derives CTR and CPC from the click count. Those figures describe media cost only: agency fees, production, ad-server fees and invalid traffic are not included, so the effective cost is usually higher than the CPM headline.
How the calculation works
- Cost = impressions ÷ 1,000 × CPM.
- CPM = cost ÷ (impressions ÷ 1,000).
- Impressions = cost ÷ CPM × 1,000.
- CTR = clicks ÷ impressions × 100; CPC = cost ÷ clicks.
Reference values
| Impressions | $5 CPM | $10 CPM | $20 CPM |
|---|---|---|---|
| 10,000 | $50 | $100 | $200 |
| 50,000 | $250 | $500 | $1,000 |
| 100,000 | $500 | $1,000 | $2,000 |
| 500,000 | $2,500 | $5,000 | $10,000 |
| 1,000,000 | $5,000 | $10,000 | $20,000 |
Worked example: CPM, CTR and CPC together
A campaign with 500,000 impressions at a $6 CPM costs $3,000. If it receives 2,500 clicks, the CTR is 0.5% and the CPC is $1.20. At a 2% CTR the same spend buys 10,000 clicks and the CPC falls to $0.30—CPM stayed the same, but the traffic cost changed fivefold.
That is why CPM alone is a poor buying metric. A cheap CPM on untargeted inventory can produce expensive clicks or no conversions. Compare cost per click and cost per acquisition, and include agency fees, production and ad-serving costs when you calculate the effective cost.
Viewability, invalid traffic and what CPM really counts
A CPM is priced per thousand impressions served, but not every impression is seen. Viewability standards count a display impression as viewable when at least 50% of its pixels are on screen for one continuous second, and video when 50% is visible for two seconds. Inventory sold on a viewable CPM basis is priced differently from raw served impressions.
Invalid traffic — bots, accidental clicks, duplicated requests — inflates impression counts without producing customers, and most platforms filter it before billing. Compare CPM alongside viewability, click quality and conversion rate. A high CPM on inventory that is never seen is worse value than a modest CPM on a page where the audience actually is.