Marketing
CPM Calculator
Calculate CPM — the cost per thousand impressions — from ad spend and impressions delivered.
Enter ad spend and impressions for the same campaign and period.
Enter your values
Media spend for the campaign over the measurement period.
Impressions delivered for the same campaign and period.
Results
CPM
—
Enter ad spend and impressions.
Ad spend
—
The spend figure entered.
Impressions
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The impressions entered.
Results are estimates based on the values entered and are provided for general planning.
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Step by step
How to use the CPM
- Enter the Ad spend for the campaign or period.
- Enter the Impressions delivered on the same ads.
- Read the CPM — the cost of one thousand impressions.
Method
How to calculate CPM
The M in CPM is the Roman numeral for one thousand — mille — so CPM is the cost of a thousand impressions, not the cost of a single impression. Divide spend by impressions to get the cost of one impression, then multiply by 1,000 to express it in the standard unit the industry quotes.
Formula
CPM = Ad spend ÷ Impressions × 1,000
Assumptions
- Ad spend and impressions come from the same campaign and reporting period.
- Impressions is a positive whole number.
- Impressions are counted as the platform defines and reports them.
- Viewability standards differ between platforms and are not adjusted for here.
The division is calculated at full precision before display. Currency displays two decimals; impressions display as whole numbers.
How to interpret the result
CPM prices delivery, not outcomes. It tells you what it costs to put your ad in front of a thousand opportunities to see, and nothing about whether anyone clicked, remembered, or bought. Rising CPM in a stable campaign usually points to increased auction competition or a narrowing audience.
Worked example: comparing a sponsorship with social ads
A newsletter sponsorship costs $900 for 150,000 impressions, a CPM of $6.00. A social campaign delivers impressions at $4.50 CPM. The sponsorship is more expensive per thousand views, so it needs better engagement to be worth it.
When to use it: converting CPM to cost per click
If the sponsorship above gets a 0.8% click-through rate, 150,000 impressions produce 1,200 clicks, an effective cost of $900 ÷ 1,200 = $0.75 per click. Converting CPM this way lets you compare impression-priced and click-priced placements on one basis.
CPM vs CPC
CPM is the price of reaching a thousand people; CPC is the price of one of them acting. The link between them is click-through rate: at a fixed CPM, doubling click-through rate halves CPC.
Buying on a CPM basis puts delivery risk on you — you pay whether or not anyone clicks. Buying on a CPC basis shifts it to the platform.
CPM vs CPA
CPM sits at the very top of the funnel and CPA at the bottom. Between them lie click-through rate and conversion rate, and either can break the connection between a cheap CPM and an affordable CPA.
Awareness campaigns are usually judged on CPM and reach; direct-response campaigns on CPA. Using the wrong measure for the objective leads to the wrong optimisation.
Frequently asked questions
Which calculator do you need?
- Want the cost per click from those impressions? Use the CPC Calculator.
- Need the cost per acquisition further down the funnel? Try the CPA Calculator.
- Measuring the revenue returned per ad dollar? Use the ROAS Calculator.
Keep calculating
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