How to use the CPM Calculator
- Choose what you want to calculate.
- Enter the two values you know.
- Read the result, with the supporting figures below it.
The CPM formula
CPM = cost ÷ impressions × 1,000. The M comes from the Roman numeral for 1,000. Spending 500 on 100,000 impressions gives a CPM of 5.
When to use CPM
CPM suits awareness campaigns, where being seen matters more than clicks. To compare it with performance campaigns, work out cost per click with the CPC Calculator.
Also searched as: cost per thousand impressions, cpm formula, calculate cpm, ad impressions calculator, media planning calculator.
Tools that pair well with the CPM Calculator
- CTR Calculator — Enter clicks and impressions to get your click-through rate, for ads, email or Search Console.
- ROAS Calculator — See what each ad dollar brings back.
- Percentage Calculator — Seven everyday percentage calculations on one page.
- UTM Builder — Add utm_source, utm_medium, utm_campaign and friends to any link, see which GA4 channel the visit will land in, and tag a whole list of URLs at once.
Frequently asked questions
Is anything I enter saved or sent?
No. The calculation runs in your browser. Your last inputs are remembered on this device only, so the page opens where you left off.
What is a good CPM?
It varies widely by platform, audience, country and season, so compare against your own past campaigns.
Does CPM mean cost per mille?
Yes. Mille is Latin for thousand.
Is CPM the same as RPM?
No. CPM is what advertisers pay per thousand impressions. RPM is what publishers earn per thousand.
Can I install CPM Calculator as a web app and use it offline?
Yes. CPM Calculator is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.