Free tool · cost per thousand impressions
Free CPM calculator
CPM is the cost of 1,000 ad impressions: total ad spend divided by impressions, multiplied by 1,000. This free CPM calculator works it out from any two of spend, impressions and CPM, so you can also find the budget a target CPM needs or the impressions a budget will buy.
By the Dolphin Analytics team · Last updated · Formula as defined in Google Ads Help (CPM)
£500.00 ÷ 125,000 × 1,000 = £4.00 - Click-through rate (CTR)
- 1.20%
- Cost per click (CPC)
- £0.33
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What is CPM?
CPM stands for cost per mille, where "mille" is Latin for thousand. CPM is the price an advertiser pays for 1,000 impressions of an ad, whether or not anyone clicks. Google Ads, Meta Ads, LinkedIn Ads and TikTok Ads all report CPM, so it is the standard way to compare what reach costs across platforms.
How do you calculate CPM?
Divide total ad spend by total impressions, then multiply by 1,000, as Google Ads Help defines it. The same formula rearranges to find the other two numbers:
| To find | Formula | Worked example |
|---|---|---|
| CPM | spend ÷ impressions × 1,000 | £500 ÷ 125,000 × 1,000 = £4.00 |
| Spend | CPM × impressions ÷ 1,000 | £4.00 × 125,000 ÷ 1,000 = £500 |
| Impressions | spend ÷ CPM × 1,000 | £500 ÷ £4.00 × 1,000 = 125,000 |
Is CPM the same as cost per click?
No. CPM prices every 1,000 impressions, while cost per click (CPC) prices each click. Two campaigns with the same CPM can have very different CPCs, because CPC also depends on how many people click. CPC equals CPM divided by 1,000, divided by the click-through rate, which is why the calculator shows both when you add clicks.
Frequently asked questions
Is this CPM calculator free?
Yes. The Dolphin Analytics CPM calculator is free, needs no sign-up and runs in your browser, so the numbers you enter never leave your device.
What does CPM stand for?
CPM stands for cost per mille. Mille is Latin for thousand, so CPM is the cost of 1,000 ad impressions.
What is a good CPM?
No single CPM is good for every campaign. CPM changes with the platform, audience, country, ad format and time of year, so the most useful comparison is against your own past campaigns on the same platform.
How do I work out the budget for a target CPM?
Multiply the target CPM by the impressions you want and divide by 1,000. Choose "Budget needed" above and the calculator does it for you.
What is the difference between CPM and vCPM?
CPM counts every impression served. vCPM, used by Google Ads, counts only viewable impressions, where at least half the ad is on screen for at least one second (two seconds for video).
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